Btrieve Developer`s Journal

Transcription

Btrieve
DevelopersJournal
®
October-December 1994
Vol. II No. 4
THEINDEPENDENTSOURCEOFNEWSANDINFORMATIONABOUTBTRIEVEANDSCALABLESQL
BTI HOSTS THE SUMMIT
Btrieve Technologies Reveals Ambitious Plans for 1995
Austin, Texas Over one hundred
representatives of organizations which use
Btrieve and Scalable SQL gathered in
Austin in October to meet with Btrieve
Technologies management and staff, and to
discuss the plans the company has for the
future. The two-day conference, organized
by BTI, was designed ...to let our
customers know about our plans, and to get
feedback from them about what their needs
are and whats important to them, said
Ron Harris, president of BTI. During his
opening remarks, he told participants not to
be shy about asking questions, adding, All
of our employees will be in and out of here
during the course of these meetings, and if
you dont ask us questions, you can bet that
were going to ask you some.
Summit participants included a
diverse mix of accounting system vendors,
corporate MIS departments, vertical
market developers, independent
consultants, and database tool vendors,
some from as far away as Europe and the
far east. Ron Harris mentioned the
international aspect of the gathering in his
opening remarks, and took the opportunity
to introduce Patrick Duboisset, recently
hired to lead BTIs European marketing
division.
The conference opened Monday,
October 10, with addresses from Ron
Harris and Nancy Woodward, BTI
chairman. Nancy outlined the evolution of
Btrieve Technologies from its inception as
Softcraft, Inc., through the ownership by
Novell, and the recent re-acquisition of the
product line by Btrieve Technologies, Inc.
She discussed BTI product introductions
during the first six months since the reacquisition, the current relationship with
Novell, and the companys strategy for
positioning its products as cross-platform
database solutions for middle-market
database customers. One highlight of
Nancys presentation was the
announcement of Built on Btrieve, a
market awareness program designed to
See Summit on page 4...
IN THIS ISSUE
The Summit
Btrieve Technologies holds a two-day
conference in Austin, Texas with leading
users of Btrieve and Scalable SQL to discuss
current strategy and future plans..............Page 1
Inside Btrieve
Doug Reilly reports on the internal structure
of Btrieve version 6.x and focuses on several
differences between v5 and v6................Page 8
Hands On Review
Steve Mook takes a detailed look into the
most common challenges users face when
they attempt to access Btrieve-based data with
Microsoft Access.....................................Page 13
BTIs Technical Corner
Photographer:JamieProvenzano
In another installment of Btrieve
Technologies Technical Corner, we provide
the latest technical information on Btrieve
and Scalable SQL including how to optimize
the new Btrieve version 6.15 engines.....Page 17
Btrieve and Scalable SQL users, BTI employees, and 3rd party vendors enjoyed the chance to meet face-to-face to
discuss the future of BTI and their products. Seminars dealt with technical, marketing, and product support issues.
Btrieve Accounting
Eric Cohen, CPA and Computer Accounting
Consultant, begins a three-part series on why
Btrieve is the best, safest, and most widely
used method for maintaining accounting
data.........................................................Page 25
And much, much more...
Volume II, Issue 4
ISSN 1071-7463, published quarterly by
Smithware, Inc.
Staff
Publisher: Scott Smith
Editor: Steve Mook
Contributors: Jon Burke, Eric Cohen, Jim
Fink, Ray Kukari, Doug Reilly
Contributors to Technical Corner: Linda
Anderson, Doris Eldridge, Mad Poarch,
Carol Rylander
Graphic Design: Arthur Austin
Design Consultant: Tania Owen Studio
Photographers: Dean Dixon, Jamie
Provenzano
Illustrators: Will Owen, Albrecht Dürer
Advertising Manager: Carolyn Lighty
Circulation Manager: Cindi Gourley
Subscriptions
Annual subscriptions are for four issues per
year at $49/year for delivery inside the
United States, and $79/year for delivery
outside the United States.
Back Issues: Back issues are available for
$20.00 per issue. Contact Cindi Gourley at
(615) 386-3100 for additional information.
How to Contact BDJ
You may address news items, new product
announcements, tips, advice, comments,
complaints, praise, or any other
correspondence to:
Btrieve Developer's Journal
2416 Hillsboro Road, Suite 201
Nashville, Tennessee 37212
Telephone: (615) 386-3100
Facsimile: (615) 386-3135
CompuServe: 73173,2731
MCI Mail: 590-5654
Internet: [email protected]
Advertising
For information about advertising your
product or service in Btrieve Developer's
Journal, call Carolyn Lighty, Advertising
Manager, at (800) 685-2403 or (201) 7120044.
Copyright 1994 by Smithware, Inc.
All rights reserved.
With the exception of the “Technical Corner” section,
this publication is produced independently of Btrieve
Technologies, Inc.
No part of this publication may be reproduced in any
form by any means without permission in writing
from the publisher.
Smithware is a trademark of Smithware, Inc.
Btrieve and XQL are registered trademarks and
Scalable SQL, Xtrieve Plus, and Microkernel
Database Engine are trademarks of Btrieve
Technologies, Inc.All other names are the trademark
of their respective manufacturers.
From
the Publisher...
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
1234567890123456789
As we at Smithware celebrate the first anniversary of
Btrieve Developers Journal, I want to sincerely thank all of you
who have supported our publication through your subscriptions,
input, collaboration, and comments. When we published our little
8-page premier issue in late October of last year, we had no idea
what a tremendous void BDJ would fill. We also could not have
predicted that the movement of the Btrieve product line would
accelerate with such force.
The end of a year always causes me to seriously consider
the future... This time, I find myself thinking about those things
that, in my opinion, BTI must do in the coming months in order
to maintain and build on their leadership position in the middle
market. The following is my proposal of these things.
They must continue to move the Btrieve Microkernel
Architecture to new platforms quickly. In addition to having a
SCOTT A. SMITH, PUBLISHER
Btrieve engine as a database server on Microsoft NT, BTI will
move into other areas as well. These areas will include IBM
LAN Server, UNIX implementations, and PIN (Processor Independent NetWare) versions of
Btrieve running on diverse platforms.
They will heavily promote the proven scalability of the Btrieve product line. BTI will
show the market that Btrieve truly is the only database manager that runs consistently and
manageably from a one-user installation on a lap-top PC, to ten users on a LAN, to a thousand
users on a WAN.
They should aggressively pursue the international market. Look for massive BTI
organization, marketing, and fulfillment throughout Europe and look for a Btrieve subsidiary
operating in Japan by Mid-1995.
They will mobilize their marketing team to help develop and promote more robust and
powerful third-party tools (yes, including Smithwares line) by creating and strongly promoting a
Built on Btrieve product identification and certification program. This program will help users of
Btrieve-based applications take advantage of the Btrieve tools that are already out there, and will
expand the market for us as third-party tool vendors. Also, look for a strong BTI commitment to
ODBC at the beginning of the year.
No one can truly predict the
future, I suppose... So lets look at this list
again in a few months to see how Im
doing.
PhotographbyDeanDixon
BtrieveDevelopers
Journal
Contents...
Inside Btrieve
Inside Btrieve 6 Files
By Douglas J. Reilly
Technical Corner
8
What has changed inside Btrieve since the
release of the version 6.x file structure? More
than you think!
Btrieve Applied
Getting a Handle on Btrieve
By James H. Fink
10
Developing applications in C just got easier:
Use Jims stdio-like method for Btrieve access
in C and you wont regret it.
Technical Supplement to BDJ
Btrieve Technologies, Inc.
Learn how to optimize Btrieve 6.x, hear
details about what in store for the future of the
Btrieve Microkernel, and get the latest tips
available from BTI.
Accounting
Btrieve Based Accounting
By Eric E. Cohen
By Steven A. Mook
25
Heres the first of a three-part series on
Btrieve and Accounting systems.
Feature Article
Hands-On Review
How to Make Microsoft® Access
17
13
The connection between Microsoft Access and
Btrieve can be difficult. Steve simplifies the
process by answering common questions.
Programming for Hire
By Jon Burke
31
From the both the clients and the contractors
point of view, Jon looks at the ins and outs
of computer consulting services.
The SUMMIT continued from page 1
build end-user awareness of products which
use the Btrieve and Scalable SQL data
management systems. BTIs cross-platform
strategy currently includes workstation
support for DOS, Windows, OS/2, and
server support for NetWare, and BTI
recently announced that it is developing a
Windows NT server in conjunction with
Microsoft. Other possible platforms
currently under review are workstation
support for Macintosh and server support
for OS/2, UNIX, and PowerPC.
Doug Woodward, BTI chief
technical officer, followed Nancy with
insights into the direction of the product
line and the Microkernel architecture.
Details of Dougs presentation are included
in The Future of the Microkernel article
in this months Tech Corner on page 19.
The conference included several
seminars on the technical and business
aspects of the new company. The Scalable
SQL product overview and feedback
session led by Bo Holland, BTI product
marketing director, touched on licensing
issues and technical questions from
developers. Questions and comments from
the audience followed, with a consensus
that ODBC support was important if not
from a development standpoint, at least
certainly from a marketing standpoint. The
discussion ultimately centered on the
challenges developers and users face when
trying to migrate data from non-relational
legacy applications to relational systems,
such as issues of data definition and
security, mission critical application
performance, and data conversion. Carol
Rylander, Btrieve product manager, led a
session on Btrieve which dealt primarily
with the new licensing structure and the
planned improvements to the Microkernel.
The scheduled after-dinner
keynote address on Monday evening, The
Info Bond: A View from a Pothole,
unfortunately had to be canceled when Rick
Segal, multimedia evangelism manager for
Microsoft Corporation, was unable to
attend due to illness. Conference attendees
instead spent the evening visiting Austins
historic Sixth Street, talking with
colleagues and BTI employees, and
watching several hundred thousand bats
stream from their nesting site under the
Congress Street bridge.
Tuesday meetings dealt primarily
with business and marketing issues,
3
including an announcement by Lori
Baldwin, BTI channel marketing director,
of proposed reseller programs, and training
and certification programs for VARs and
consultants. Mad Poarch, VP for customer
relations, presented a seminar on BTIs
proposals for fee-based technical support
options, and distributed a questionnaire
soliciting comments and customer
feedback. This questionnaire was also
posted on the CompuServe BTRIEVE
forum so that customers who did not attend
could add their input.
The meeting ended with a
question and answer panel discussion with
Ron Harris, Doug and Nancy Woodward
in which the panel addressed questions
submitted by attendees throughout the
course of the conference.
Reaction to the Summit was
generally very positive. Most of the
conference attendees considered BTIs
willingness to share strategy and solicit
feedback to be a helpful and refreshing
change from the way in which many of
their suppliers do business, and most
appreciated the opportunity to meet with
their colleagues and with BTI staff.
BTI officials said that based on
the positive feedback from the first
meeting, more Summit meetings will be
planned for the future. ²
Duboisset to
Head BTI Europe
Austin, Texas
BTI has appointed
Patrick Duboisset, a
former Novell
executive in Europe,
to the post of
Director of European
Market
Development.
Patrick
will be responsible
Patrick Duboisset
for positioning and
supporting BTI in Europe. He will work to
strengthen distribution channels with valueadded partners in all sectors of BTIs
relationships abroad, said Laurie
Wisbrun, a BTI representative.
Patrick was with Novell in
Southern Europe from 1989 through 1993
where he was responsible for increasing
Novells market share from 40 to 65%
throughout the region.
According to Mr. Duboisset, My
ambition is to build strong distribution
partnerships, and identify and appoint
authorized solutions integrators, and to
make BTI the industry de facto standard in
the departmental database engine market.
NewsBriefs
BDJ Executes Distribution Agreement in Japan
Nagoya, Japan An agreement to distribute Btrieve Developers Journal to the Japanese
market has been executed between Smithware, Inc., publishers of BDJ, and AG-Tech
Corp., the leading supplier of Btrieve support and services in Japan. According to Steve
Mook, Smithwares Vice President for Development, We are pleased with AG-Tech
Corps decision to become involved with our magazine because we recognize the vast
global support that Btrieve enjoys, particularly in Japan. AG-Tech will provide additional
material pertinent to the Japanese perspective in the copies of BDJ that they distribute. For
additional information, contact Smithware at (615) 386-3100 or AG-Tech Corp. in Japan at
(052) 951-2706.
Synex Systems Readies @Trieve for Excel
Vancouver BC, Canada The leading manufacturer of spreadsheet links for Btrieve files,
Synex Systems, is preparing to release a new version of @Trieve for Excel. @Trieve hot
links data from any indexed Btrieve file directly into an Excel sheet through the use of
commands, functions, and macros on a read-only basis. If a user sets up Excel sheet
templates with @Trieve, it is then possible to pull live data into Excel at any time with the
click of a button. @Trieve is compatible with:local and requester versions of Btrieve 5.x,
6.10, and 6.15, and with Excel versions 4 and 5. Additional functionality may include a file
query command to assist users in pulling data via dialog screens with the option of saving
these queries as macros, and enhanced screens for specifying index requests. Contact Synex
Systems for additional information at (800) 663-8663 or (604) 688-8271, Fax: (604) 6881286, BBS: (604) 688-2351, or GO SYNEX on CompuServe.
Vol. II, No. 4 October-December 1994
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
Briefly Noted
Business Tools, Inc. (919-932-3068)
has announced the release of TAS
Professional version 5.0, the latest
release of their popular modular
design environment for accounting
and business information systems...
Solomon Software (419-424-0422)
announced that both of its accounting
product lines, Solomon IV for
Windows and Solomon III for
Btrieve, will be available on
Microsoft Windows NT Server 3.5,
as well as on Novells NetWare.
The company announced that
Solomon IV Server Edition, which
runs on Scalable SQL, also will be
available on Windows NT Server.
Solomon also has introduced a
multimedia demonstration CD-ROM
of their Windows-based accounting
software... Btrieve Technologies
Inc. (512-794-1719) is looking for
beta sites for the Windows NT
Btrieve engine. Send company name,
address, contact name, CompuServe
account ID, and the timeframe in
which you are available to actively
test the beta software to the BTI CIS
account, 74431,3337. The Btrieve
for OS/2 v6.15.1 pre-release is now
available in the CompuServe
BTRIEVE forum to anyone who
wants to try it out. You may
provide feedback in forum section
13. This pre-release may contain
some areas of functionality which
have not been perfected... Magic
Advisor International (301-7794709) has been formed to publish a
new magazine entitled MagicCom,
the Magic Communications
Magazine. The bimonthly
publication features articles of
interest to developers who use the
Magic development tool from Magic
Software Enterprises. Subscriptions
are $49/year in the US and Canada
and $99/year elsewhere... IQ
Software Corporation (404-4468880) is shipping their new IQ for
Windows version 4.0. IQ is a clientserver query and reporting tool that
supports many databases including
Btrieve and Scalable SQL...
4
MICROSOFT-BTI ANOUNCE PACT
Agreement to Deliver Client-Server Btrieve
Database Engine for Windows NT
Atlanta, Georgia Microsoft and Btrieve
Technologies, Inc. (BTI) announced an
agreement to deliver and jointly market
the Btrieve database engine for the
Windows NT Server operating system.
Under the terms of the agreement, the two
companies have agreed on a broad set of
joint marketing programs that are intended
to introduce Btrieve and Windows NT
customers to the benefits of the combined
technology.
The joint agreement was
announced as part of a keynote address
delivered at NetWortd+Interop by Jim
Allchin, vice president, Business Systems
Division of Microsoft, and Ron Harris,
President and CEO of Btrieve
Technologies.
As part of this agreement,
Microsoft will include a coupon in every
package of Windows NT Server that can
be redeemed for a ten-user version of the
client-server Btrieve database engine for
Windows NT for a promotional price of
$99. After one year, BTI plans to offer an
attractively priced, shrink-wrapped
package of Windows NT Server and
Btrieve through its distributors.
“This agreement makes it easy
for Btrieve customers to get the
scalability, portability and reliability of
Windows NT Server,” said Allchin.
“Customers using the many applications
built on Btrieve for industries including
insurance, banking, health care,
manufacturing and accounting can now
adopt Windows NT easily.”
In April of this year, BTI
acquired Novell’s database product line
and began aggressively investing in new
marketing, sales and development
programs, including the expansion of the
product line to new platforms. This is the
first announcement of BTI products
available for Windows NT.
“The combination of Btrieve,
Windows NT Server, and the Visual Basic
programming system provides a powerful
platform to meet the growing needs of
small, medium, or departmental
organizations,” said Ron Harris. “The
agreement is a big win for the more than
one quarter-million sites in North America
running business-critical Btrieve
applications today.”
With this announcement,
Microsoft and BTI officials confirmed that
Btrieve applications can now
automatically scale from mobile laptops or
notebooks to large client-server
configurations with symmetric
multiprocessing hardware without
changing a line of application code.
Production shipments of Btrieve
for Windows NT are scheduled to begin
by the first quarter of 1995. ²
Crystal Reports 4.0
Released
Vancouver BC, Canada Crystal has
announced major new versions of
Crystal Reports and the Crystal Reports
Server.
We have increased the speed
dramatically, said Greg Kerfoot,
President of Crystal Services and
Director of R&D. We have also
provided the end user with the ability to
get the information they require with
the Crystal Reports Server 4.0.
Crystal claims that thier totally
re-designed report engine with Smart
Engine Tecnology greatly increases
performance over previous versions,
with reports being generated 2-10 times
faster than before.
Crystal Reports version 4.0
also includes Experts, which prompt
users for choices, and then do reporting
tasks for them automatically.
Improvements to the user interface
include a new tab interface, ruler,
Best Fit button, automatic styles, and
a new grid with on/off and visible/
invisible options.
The version 4 release also
adds 20 new direct-call functions to the
developer interface of its report engine,
and has added a new OCX object in
addition to its Visual Basic VBX
interface.
Contact Crystal Services at
(800) 877-2340 or (604) 681-2934.
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
copy that is not current. If the change is made successfully, the
counters are changed and Btrieve will know which file control
page is correct. If the change is not completely written, no harm
is done, since the file control page will still be the copy that was
correct before the change was begun.
Halt! What file type goes there!
Inside Btrieve 6 files
By Douglas J. Reilly, Access Microsystems, Inc.
When I first mentioned to the folks at Btrieve
Developers Journal that I wanted to take a look at some of the
differences between Btrieve version 5.x files and version 6.x
files, I had no idea how great the differences between the two
file types would be. Was I in for a shock!
For details of the version 5.x format, I refer you to
Special Assignment... Btrieve File Recovery in the JanMarch 1994 BDJ (Vol. II, No. 1). One of the major changes in
how Btrieve works for Version 6.x is the elimination of preimaging files which were used in prior versions of Btrieve to
maintain file integrity. In Btrieve version 5.x, before changes
were made to the Btrieve file, the original pages were written to
a file with the same name as the Btrieve file, but with an
extension of .PRE. It is for this reason that you were never to
create Btrieve files that had a file name that differed only in the
extension (for instance ORDER.HDR and ORDER.DET).
Btrieve 6.x files do not create pre-imaging files, however the
naming restriction remains the same, since Btrieve does in some
cases (continuous operation) create special files with extensions
of .^^^.
How does Btrieve version 6 ensure that information is
properly written or restored? This brings us to the first major
change in the internal structure of Btrieve files for version 6.
Look at figure 1. This shows beginning of the first page of a
Btrieve file in a hex
I had no idea how
editor. Note that the first
two characters on the
great the differences
page are 4643 hex (the
characters FC, I
between Btrieve version 5 assume for File
Control). All pages in
and 6 would be. Was
a Btrieve file now have
some identifier in the
I in for a shock!
first two bytes. The most
fascinating thing about the
file control page is that there is another instance of that page
directly following it. This is where it gets interesting. On each
of the file control pages, there is a counter that is checked by
Btrieve to allow it to determine which copy of the file control
page is current. When changes are made, they are made to the
5
An interesting side trip is in order. On several
occasions, I have had Btrieve developers who wished to
determine if any arbitrary file was a Btrieve file. After I
attempted to get them to simply try and open the files using
Btrieve, I was able to give some answers for version 5.x files,
but they were at best hints and rules of thumb. What follows is a
fairly surefire way to determine the if a file is a Btrieve file.
First, check the length of the file. If it is not divisible by 512,
forget it. This is not a Btrieve file (or it could be a very badly or
strangely damaged Btrieve file). Next, open the file in binary
mode and read the first 10 bytes. The first 4 bytes will be 46 43
00 00 hex. Next, look at the tenth byte. This should be an even
number between 2 and 16 inclusive. If not, this is not a Btrieve
6.x file. This is the number of 256 byte blocks in the page size.
Calculate the PAGE_SIZE (if 2, PAGE_SIZE=512, if 4,
PAGE_SIZE=1024) Next, read the 4 bytes exactly
PAGE_SIZE bytes from the beginning of the file. These four
bytes must also be 46 43 00 00 hex. If they are, you can be
reasonably assured that it is a Btrieve 6.x file.
Page Allocation Table (PAT) Pages
After the file control pages, there is a new type of page
in Btrieve 6.x: Page Allocation Tables, or PATs. The only
reason this may sound familiar to some of you is that BUTIL
may have reported to you that the PATs are damaged. What
exactly do these PAT pages do? Look at figure 2 to see the first
portion of a PAT page. Like File Control Pages, PAT pages
come in sets of two. Just like the File Control pages, the PAT
pages have a usage count used to determine which of the pages
is the current good PAT page. Perhaps even more interesting
is the fact that there exists a second way that Btrieve can use to
determine which PAT page is the current PAT. There is a 32 bit
bitmap (I believe in the FC page) that Btrieve can use as a
reality check to ensure that the correct PAT is in use. Those
database folks out there may have already noticed a potential
Figure 1 - The Beginning of the First Page of a version 6.x
Btrieve File
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
When I was first poking around with Btrieve 6.x files,
the first thing I wished to determine was the layout of records
within the data pages. This is important to me as the developer
of recovery utilities that sometimes go the extra mile beyond
simply using Btrieve calls to do the file recovery. In some
cases, I would simply go from page to page, searching for
possible data pages by trying to set the record position (using
the SET_POSITION operation code 22) to the first slot on a
page and testing for status 43 (invalid positioning). If I got a
43, I assumed the page was not a data page and moved on,
otherwise, I tried every possible record start position on the
page, based upon what I knew about the record length and the
number of keys that allowed duplicates. The number of keys
that allowed duplicates was important because pointers to the
Figure 2 - Page Allocation Table Page
previous and next record for each duplicate key had to be
stored. For details, I once again refer you to Special
problem with this scheme: Forgetting for a moment what you
Assignment... Btrieve File Recovery in the Jan-March 1994
have to do when your 32 bit bitmap is filled up (it sure sounds BDJ (Vol II, No. 1).
ugly to me), what is the rule for data stored twice? Thats
When I started looking at the pointers, it was
correct! If data is stored twice, there is a good chance that it
apparent to me that something was different. The pointers did
will be stored incorrectly in one of those places. The folks at
not seem to be quite right. For example, look at figure 4. At
BTI recognized this as well, and removal of this bitmap is one
offset 3356 there is a pointer to a next or previous record (I
of the minor changes between
am not certain which as I write
the 6.10 Btrieve NLM/Requester
this, but I assume it is a next
and the 6.15 file format.
pointer). Because of the way
The first two bytes on
numbers are stored in Btrieve
the PAT pages are 5050 hex (or
files (not Intel format) the hex
the characters PP, perhaps for
numbers 00002005 represent hex
PAT Page). After some header
520 or decimal 1312. This is
information, the PAT page
from a 512 byte page size
consists of many 4-byte pointers
Btrieve file, and so we know that
to pages within the file.
this cannot be a direct pointer,
Actually, the pointers are 3
since the four pages allocated to
bytes, since one of the bytes is
FC and PP pages mean that as a
used to indicate what type of
direct pointer using the
page is pointed to by the
beginning of the file as a basis, it
Figure 3 - Data Page
pointer. Looking carefully at
would point into the first of the
figure 2, notice that at offset
PP pages. Then I tested the offset
1549 there is a character D (hex 44). This tells us that the
from the end of the FC and PP pages, 512 times 4 (for the 4
page referred to by this particular pointer is a data page.
FC and PP pages) plus 1312, gave me 3360. 3360, as you can
(Other known values that can be embedded into the pointer
see in figure 4, is the byte hex 01 just before the next record
are A for Alternate Collating Sequence, V for Variable tail
begins, and so the mystery was solved. The previous and next
data, and any value over hex 80 for indexes, with the a page
pointers were pointers from just beyond the FC and the PP
for index 0 being denoted by a value of hex 80, a page for
pages. At first I thought this might just be a way to get
index 1 being denoted by a value of hex 81, etc.) At offset
slightly beyond the 4 gig limit on file size, but then the
1550, notice the hex value 06. From this we know that the
page that this pointer refers to is at offset 6 times the page size
(in this case, 6 x 512, or 3072). Sure enough, as we look at
figure 3, we find at offset 3072 what looks like a data page.
The number of pointers varies with the page size.
Take the page size, divide it by 4, subtract 2 for some header
information on the PAT pages themselves, and you have the
number of page pointers you can find on a given PAT page.
For instance, if the page size is 4096, divide that by 4 and
you get 1024. Subtract 2 and you have 1022. So, from this,
we know that in a file with a page size of 4096, each PAT
page contains pointers to 1022 pages, or 4,186,112 bytes of
data. This is, of course, far short of the current stated limit for
Btrieve files of 4 gig. How does Btrieve keep track of
Figure 4 - Another Data Page
additional pages? Therein lies a tale...
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
limitation
to the PP page
setup
Vol. II, No.
4 October-December
1994
sank
in. Since
a single PP
page
Btrieve
Developer's
Journal
mechanism to allow multiple PP pages. If pointers are based
upon distance from the PP page that a particular page reports to,
this could have the effect of eventually (when ported to an
operating system that supports it) removing Btrieves 4 gig file
size limit. Very neat indeed!
Getting back to my immediate problem, that of trying
to recover data from badly damaged files, one thing that had
served me well in the past was to simply eyeball the file and
from that determine where data would be. It soon became clear
that this was not going to work with Btrieve version 6.x files.
For example, if I add a single record to a Btrieve 6.x file, it will
appear neatly once in the file. However, if I then add a second
record to the file (assuming that the record does not take up an
entire page), you will find that there are two instances of the
first record in the file: The original instance, on a page by itself,
and another copy on the page where the second record has been
added. It appears that Btrieve writes the new page (with both
records) and if all is well, commits the new page, but does not
obliterate the old page. This is important, because if you are
writing a grungy routine to salvage records from a damaged
file, you may well get much more than you bargained for. The
issue is even more confusing when rather than entering a new,
second record, you are simply editing the first record. Then
determining which page is the good page is even more
complex. This has required a bit more study than I had
originally anticipated, but rest assured that a coherent strategy
for getting at the real data will appear in my next Inside Btrieve
column.
In order to see what type of error will give a PAT
error, I got out my trusty hex editor and purposely messed up
the file in several ways: I changed the values of pointers on the
PAT page (making sure I was using the copy of the page that
was currently good). I changed the D embedded in the
pointer to indicate that the pointer pointed to a data page to a
Getting a Handle on
Btrieve
by James H. Fink, The PROMPT Corporation
Using the Btrieve application interface for the C
programming language can be an error prone and frustrating
experience, even for experienced programmers who are familiar
with the Btrieve API. The integer function BTRV() which
7
Q (a value I am not sure would ever be valid). Much to my
surprise, BUTIL -SALVAGE never reported an error. My
programs could still read and write the file, and even more of a
surprise, after the write to the file, the PAT page was healed.
All the bogus values I placed in the PAT page were now
replaced with the proper values. Very strange!
In fact, while I know that PAT errors occur, and I am
fairly sure I know what should cause them, I am thus far (using
Btrieve 6.15 for DOS) unable to cause one to occur. Like the
previous problem (and it IS a problem if you cannot cause a
failure to occur as you would expect), I anticipate I will be able
to resolve this over the next several weeks.
To be Continued...
The scope of the internal changes to Btrieve version 6.x
files has been a surprise to me. BTI has done many wonderful
things with the Btrieve file format, and yet has managed to
allow old programs to continue to function. This is the beauty of
detail hiding. Next time, we will continue to expose some of the
details of Btrieve file internals. I dont expect you will need to
use (or should use) the gory details to do the bulk of your work,
but these details can be critical when that call comes telling you
that a catastrophic failure has occurred on a critical Btrieve file,
and that week-old backup just wont do. ²
Doug Reilly is the owner of Access Microsystems Inc., a software
development house specializing in C/C++ software development, often
using Btrieve as a file manager. He has had articles on Btrieve published in
Dr. Dobb's Journal and is also the author of BTFILER and BTVIEWER
Btrieve file utilities available on CompuServe. Dougs CompuServe address
is 74040,607 and can be contacted at 404 Midstreams Road, Brick, NJ
08724 or at (908) 892-2683.
provides all access to the Btrieve record manager, has 6
parameters, and arguments for all 6 must be provided regardless
of the Btrieve record operation being invoked. But, depending
on which of the 35 operations the programmer is invoking, the
content and use of the arguments changes. Some of the
arguments involve complex type casting, and others are buffer
lengths that may vary over time. If an error is made when
providing an argument, Btrieve error messages are often
cryptic, and sometimes misleading, causing frustrating
debugging sessions. Use of the BTRV() function for even the
simplest processing of a table provides ample opportunity for
error. To sequentially process a table on an index, the
programmer has to open the table, get the first record,
repeatedly get next records, and close the Btrieve table. A
minimum of 24 arguments must be correctly supplied to
successfully complete this task.
This article will explain a method of dealing with these
problems so that the application programmer can concentrate on
using Btrieve to solve his or her application problem.
The method uses a model that will be familiar to all C
programmers --the stdio model. When processing a file using
stdio, the programmer communicates with the file system using
an integer handle or a pointer to the file provided by stdio that
minimizes the chance for error by limiting the frequency with
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
which the programmer must specify information.
An Example
Figure 1 demonstrates how this method achieves the
goals of reduced program complexity when accessing Btrieve
tables. It depicts a fragment of a program designed to
sequentially access a table. The program will process an
insurance policy table from the first record to the last on index
0, in read-only mode.
#include "bt.h" //the btrieve handle access routines
//structure for policy table record
struct POLICY_REC {
char PolicyNum[7];
char PolicyData[93];
}rec;
Figure 2 - The BT_FILE structure
A word is in order about the field SQL_name. This
method was implemented in a Novell 3.12 production
environment supporting multiple Btrieve tables of 1 GB or
more, using NetWare SQL. These tables frequently change
location due to space constraints. To accommodate this, we
established the convention of the Table Directory table which
is always located on the SYS: volume in a particular directory.
This table contains the SQL name of the file (such as Policy
in SELECT * FROM Policy) and its current full path name.
This approach allows for a significant measure of device
independence, as will be demonstrated below.
//structure for policy table key 0
struct POLICY_KEY0 {
char PolicyNum[7];
}key;
int main(int argc, char** argv) {
Handle policy;
//Handle is a typedefld int
//inititalize table with the SQL name "Policy"
//rec is the data buffer, key is the key buffer
policy=bt_init("Policy", BT_readonly, 0, rec, key);
}
typedef struct BT_FILE {
int handle;
//the handle for the table
char SQL_name[20];
//optional table used in SQL queries
char full_path_name[64];//full path name of table
int open_mode;
//readonly, readwrite, etc.
int index;
//the index
int status;
//last status code returned for table
char* data_buffer;
//pointer to the buffer for the table
int data_length;
//the length of the data buffer
char posblock[128];
//Position Block
int opcode;
//the last opcode used for the table
char* key_buffer;
//pointer to the key buffer
int key_length;
//the length of the key buffer;
long record_count;
//total recs in table at open time
} bt_file, *pbt_file;
//get the first record
bt_getfirst(policy);
Initializing the Structure
do {
//process each record
}
while (bt_getnext(policy) != BT_eof);
To support this method, I developed the concept of
initializing a Btrieve table. Normally, when processing a
table, one need only open it. Initializing a table initializes the
BT_FILE structure, opens the table, and does a stat operation
on the table. Figure 3 shows the function prototype for
bt_intialize().
bt_close(policy);
int bt_initalize(char* SQL_name, int open_mode, int index,
char* databuffer, int datalength, char* keybuf, int
keylength);
Figure 1 - Btrieve programming using the stdio model.
The Approach
Figure 3 - Prototype for bt_intialize
Figure 2 shows the typedef declaration of a C structure,
and a pointer to that structure, which I used to implement this
method. The approach is to allocate and fill one of these
structures for each unique Btrieve table access path (i.e. table
and index) required by a program. The function doing the
allocation will assign the structure a unique integer handle, and
return that handle to the caller. Thereafter, the caller invokes
Btrieve record operations by specifying the operation and the
handle.
Included in the method is a means of soft coding the
location of Btrieve tables so that they can be moved and located
at run-time without recompilation. The structure and its
associated functions are partitioned in such a way that the
programmer never directly deals with the structure. The only
way the programmer changes the structure is with the associated
functions.
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
This function searches the Table Directory table for
the SQL_name, captures the current full-path name of the file,
dynamically allocates and constructs the BT_FILE structure,
opens the table, does a stat operation on the table, and fills in
the number of records on the table. If successful, the function
returns a positive integer handle which will be used for all
subsequent access to the table.
In practice, calling this function proved tedious as
structure addresses had to be cast to character pointers. To
provide relief, I devised the macro bt_init shown in figure 4.
//bt_init macro use to simplify calls to bt_intialize() function
#define bt_init(SQL_name, mode, index, buffer, keybuffer) \
bt_intialize(SQL_name, mode, index, (char*)&buffer,sizeof(buffer)\
(char*)&keybuffer, sizeof(keybuffer))
Figure 4 - bt_init Macro
This reduced the number of arguments required to initialize a
Btrieve table from 7 to 5, as the macro computed the lengths of
the data and key buffers and performed the appropriate type
casting.
Practice also revealed that there were times when we
wanted to open a table not identified in the Table Directory
table, so I developed a hard initialization function to allow the
programmer to provide the full-path name of the Btrieve table to
be processed.
Accessing the Table
Once a handle has been obtained, all subsequent access
to the table is greatly simplified. The function bt_access(),
prototyped in figure 5, manages all record operations for the
table. The bt_access function takes as parameters the handle and
the record operation code. It then looks up the BT_FILE
structure allocated for that handle to collect all the data
necessary to complete the requested record operation, and
executes it.
Some operations require that additional information be
placed in the key buffer or data buffer. For example, a Get
Equal operation requires a search argument in the key buffer.
In these cases the programmer simply places the data in the
appropriate buffer before invoking the bt_access() function.
The integer returned by the bt_access() function is the
Btrieve return code.
Error Handling and Status Reporting
To provide easy error handling, I established a global
Boolean variable, bt_robust. This variable may be set or reset at
any time. When this variable is TRUE, Btrieve error conditions
encountered by the bt_access() function are returned to the
caller. The caller can then deal with them as needed. When this
variable is FALSE, the program will halt and issue an
appropriate error message. This is useful in the early
development stages so that energy is directed at building the
application, not error handling. Certain ambiguous errors, for
instance a duplicate key while inserting, are always returned to
the caller for processing so that the programmer can determine
within the context of the application if an error has actually
occurred.
To aid in status reporting, I established a global integer
variable, bt_status. The last status code returned by Btrieve is
always placed in this variable, so that status checking can be
delayed.
In Conclusion
The simplicity, readability, and focus of this method as
compared to the use of the standard BTRV() function speaks for
itself. The method is also easily adaptable for a C++
implementation. ²
int bt_access(int handle, int opcode);
Figure 5 - bt_access Prototype
Once again, it proved tedious to remember and supply
all 35 opcodes, so I defined manifest constants and mnemonic
macros for each of the principle record operations, as shown in
figure 6.
#define BT_geteq
5
#define BT_getfirst 12
#define bt_geteq(handle) bt_access(handle,
BT-geteq)
#define bt_getfirst(handle)
bt_access(handle, BT_getfirst)
//etc. etc.
Figure 6 - Mnemonic Defines
Closing Up
The function bt_close(handle) closes a table, and
returns the memory allocated for its BT_FILE structure to the
heap. A happy by-product of this approach was the function
bt_closeall(void), which allowed the programmer to be certain
that all tables were correctly closed and memory returned to the
heap, without any special coding techniques to track which
tables might be open or closed. This was particularly useful for
handling ABENDs occurring in the middle of opening multiple
tables. The ABEND is handled by issuing a bt-closeall(), and
exiting.
9
AcquiringtheSoftware
Building and testing the software to
implement this approach should take you less
than a week. The author recommends doing
so if you want to learn the ins and outs of
Btrieve.
If you would like to acquire the source code,
object code, library, and documentatation for
his implementation of this method, including
a full function dynamic memory manager
and linked list processor suitable for
compilation by Microsoft C version 6.Oa
through Microsoft C 8.0, kindly remit
$50.00 to:
The PROMPT Corporation
90 Mill Street
Lincoln, MA 01773
Please specify 3.5" or 5.25" format.
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
How to Make
Microsoft Access
®

A short, practical guide up the slippery slope.
by Steven A. Mook, Smithware, Inc.
Email: [email protected]
Experience has shown that Microsoft Access is a very
powerful database query tool. Experience has shown that
Btrieve is a very fast, very reliable database engine. And
experience has shown that hooking the two together is rather
like bringing elephants over the Alps. Once you get to the top,
all you need is a really big sled. The trick is in getting to the
top. The questions used in this article were adapted from
messages posted on the CompuServe MSACCESS support
forum from July through October 1994, and they represent some
of the more common pitfalls.
Access returns Unexpected error from external database
driver [20] whenever I try to attach to Btrieve.
As with the other Unexpected error from external
database driver errors, the number in brackets is the actual
status number returned by Btrieve. Which means that you have
at least one piece of Btrieve for Windows out there to return a
status. But do you have the right piece, or enough of the pieces?
Microsoft Access requires a Btrieve for Windows
engine in order to open Btrieve files. Status 20 indicates that
Btrieve for Windows is not loaded. As often as not, this error
message means you simply dont have a Btrieve engine for
Windows. Microsoft pulled it from the Access box shortly after
the release of version 1.0, following a license disagreement with
Novell, which held the copyright at that time.
Application programs which run in DOS dont use the
Btrieve for Windows drivers to access their files. They make
record requests to a terminate-and-stay-resident (TSR)
executable program in DOS, BTRIEVE.EXE, but this program
is not accessible to Windows applications. There is also a clientserver version of Btrieve which runs on Novell NetWare, which
allows server-based access to files on NetWare drives.
Workstations on the network accessing these data files run a
TSR called BREQUEST.EXE. This requester transmits
requests for information to Btrieve running on the NetWare
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
server as a NetWare Loadable Module (NLM), receives the
results from the server process, and passes them back to the
application.
Btrieve for Windows also has both a local and a clientserver implementation. The local implementation is required to
process any files not accessible to a server process (such as files
on a local hard drive as opposed to files located on a network
server running NetWare Btrieve). Local Btrieve for Windows
version 5.10 is implemented as a dynamic link library called
WBTRCALL.DLL, or WBTRLOCL.DLL if configured to run
in conjunction with the NetWare client-server version of
WBTRCALL. The size of this file is about 51K bytes. It links
directly to the application and performs all Btrieve file I/O.
The new Btrieve Client Engine for Windows, version
6.15, is implemented as a Windows executable program called
WBTR32.EXE. There is still a WBTRCALL.DLL, but it is
much smaller than the Btrieve version 5.10 DLL, as it does not
handle any file I/O itself. WBTRCALL.DLL determines
whether a Btrieve request should be routed to the local or to the
server engine based on settings in the configuration file
BTI.INI. WBTRLOCL.DLL acts as an interface between the
requester interface, WBTRCALL.DLL, and the Btrieve for
Windows Client Engine, WBTR32.
Until Btrieve Technologies releases a true DLL
requester for Windows, BREQUEST.EXE remains a critical
link in the Windows implementation of NetWare client/server
Btrieve. WBTRCALL.DLL routes requests for server-based
data from the application to BREQUEST via a DOS Protected
Mode Interface (DPMI). The client/server WBTRCALL.DLL
will attempt to pass requests for local data on to the
WBTRLOCL.DLL for processing, either internally (in version
5.10W), or via WBTR32 (in version 6.15).
The key to this error is simply that you must have
Btrieve on your system where it can be loaded by Access.
Though you may have DOS applications which can access
Btrieve files, you may not have what you need for a Windows
application to access those files, as the DOS and Windows
Btrieve client engines are different. If you have a Novell
network, then you do have the Windows run-time engine for
Btrieve as well, but Btrieve must be loaded and configured
properly as an NLM on your server, and BREQUEST must be
loaded prior to Windows. For access to non-NetWare drives,
you must have one of the client engines, either the 51K version
5.10 WBTRCALL.DLL, or the version 6.15 WBTR32.EXE.
I have a Visual Basic application using Btrieve, but I dont
have access to any data dictionary (DDF) files. I guess the
DDF information is embedded in the Visual Basic code,
which I dont have access to. Is there any way to pull the
data into Access?
Good guess. And the answer is no. There is no
practical way to pull data from Btrieve tables into Access
without DDF files which define the Btrieve data. Probably the
vast majority of Btrieve-based programs were written without
DDF files. Up until a couple of years ago, most people
developing Btrieve-based applications didnt even know what a
DDF was. Btrieve stores and retrieves records as blocks of data
based upon predefined indexes within the data, and does not
concern itself with whats in the non-indexed portion of the
records. Naturally, the application which files the data can be
counted upon to understand how to interpret it.
But in order to pull meaningful information from a data
file, a generic database front end or report writer such as Access
has to have a list telling it where the discreet pieces of
information, or fields, are in the record. Thats essentially what
a DDF is; a list, or actually, three related lists, FILE.DDF,
FIELD.DDF, and INDEX.DDF, which tell Access what the
files are in your data base, where and in what storage format the
fields are within the records in those files, and what fields are
indexed.
The best place to get DDF files is from the application
developer. The second best method is to get field layouts of the
data files from the developer, and use them to create the DDF
files yourself. The last resort method is to hack the data files by
opening a file, looking at the raw data, and finding known
values for fields within an individual record. Either of the first
two methods is vastly preferable to the third.
There are some Btrieve data files which simply cannot
be defined using DDFs. If, for instance, the programmer stored
some critical piece of information in a storage format which is
not one of the standard DDF field types, that information will
not be available to Access. The DDF standards were developed
to define SQL data, and Btrieve data stored by non-SQL
applications may not conform to the standard DDF definition
rules.
When I try to attach Access version 2.0 to one of my Btrieve
version 6.x data files, I get Unexpected error from external
database driver [7]
Youre in luck, its just a bug. Your problem stems
from a bug in the first release of the Microsoft Btrieve driver,
BTRV200.DLL. Its been fixed. Theres a new one available
on CompuServe in the MSACCESS forum library. The file
name is BTR200.EXE, a self-extracting zip file containing
everything you need to make the problem go away. Dont you
wish they were all that simple?
When I try to look at the records in one of my Btrieve tables,
Access tells me it encountered an Unexpected error from
external database driver [22]
Your Btrieve file and your DDF definition for that file
seem to have lost touch with one another, and its fortunate for
you that youre still looking at Windows, and not at a black
screen, a locked keyboard, and the perpetual flicker of a hard
drive trying to find its boot sector. Access relies upon the DDF
definition to tell it what to expect from Btrieve, and in this
instance, the DDF lied. The error indicates that when Access
asked for a record, Btrieve found a longer record in the file than
the one Access requested. Check your DDF definition to make
sure that all of the fields in the record are defined, and, if you
have variable-length records in your data files, that the last field
in your definition is a variable-length field type (either a NOTE
or an LVAR type field) with a length sufficient to hold the
longest record in the file.
I get a GPF when I try to attach a Btrieve table in Access.
Welcome to the wonderful world of modular software
design. Your GPF means that somebody in the long chain of
command between the disk drive and your application screen
stepped on somebody elses memory address. Finding out who
11
did it is essentially a snipe hunt.
The GPF message box will tell you in what module,
and at what address, the error occurred. This is not necessarily
meaningful information, as one module can set up the conditions
which will percipitate a GPF in another module. But it's a
place to start looking. A GPF in BTRV200.DLL or in
MSAJT200.DLL usually indicate that the fault had something to
do with Access, or with the DDF definition of the file, which is
what Access uses to know what to expect from Btrieve. An
error in WBTRCALL, or one of the other Btrieve components,
usually indicates a problem with your Btrieve configuration.
The weak link in this chain, if youre using NetWare
Btrieve, is the DPMI layer between WBTRCALL.DLL and
BREQUEST.EXE. Its critical that these two be matched
correctly, or a GPF is a relative certainty. If youre not sure,
you can download compatible versions of both in the file
BTRREQ.EXE in the NOVLIB forum on CompuServe. Should
the GPF persist, strip anything out of DOS that doesnt look as
if it absolutely has to be there, and try again. If this cures the
problem, you can begin carefully adding back device drivers and
TSRs until the whole thing blows up again. If youre really,
really lucky and the solar flares have died down, it might just
keep working.
But seriously, when this fails, the next most likely
problem is that youve got an old piece of something loading in
Windows where a new piece is supposed to fit, and the most
likely culprit is Btrieve. Windows programs load modules called
dynamic link libraries, or DLLs, which provide specific
functions the programs need. Btrieve for Windows uses DLLs
to hook into other programs. Windows hunts for dynamic link
libraries first in the directory with the executable that wants
them, then in the \windows\system directory, then it starts down
the primrose PATH. And it loads the first match it finds. So
now you must do likewise, and go rooting around through your
\access directory, your \windows and \windows\system
directories, and all the directories in your path (dont forget
network directories, especially the NetWare \public directory),
looking for outmoded Btrieve DLLs. Delete them, rename
them, but one way or the other, get them out of harms way.
I installed the Btrieve for Windows drivers, found a set of
DDF files, and tried to open FILE.DDF. Now I get Invalid
entries in [Btrieve] section in WIN.INI What did I miss?
Perhaps the most frequent and least informative of the
Microsoft Access/Btrieve error messages, this one sends you
looking for a section in WIN.INI which may not even exist, and
gives you no indication of what you need to do when you get
there.
The Btrieve Client Engine reads its initialization
parameters from WIN.INI or BTI.INI, depending upon which
version of Btrieve youre using. The NetWare Btrieve NLM
reads its configuration options from the server BSTART.NCF
file, configured using BSETUP. But Access requires the
[btrieve] section in WIN.INI regardless, with an options=
initialization string. The file BTRIEVE.TXT in your \access
directory explains the recommended and required settings for
these options. The recommended options line looks like this:
options=/m:64 /p:4096 /b:16 /f:20 /l:40 /n:12 /t:c:\btrieve.trn
If you're using the local Btrieve version 5.10W DLL, this
options line in WIN.INI will initialize Btrieve correctly. If
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
you're not using this driver, however, the options that Access
checks and the options you end up using with Btrieve may not
be the same options, and this can lead to aberant behavior in
Access.
The most important consideration is that Btrieve
transaction precessing be enabled. Access uses transaction
processing for its own purposes, one of which is apparently to
protect the DDF files from the possibility of destructive reads.
If you're using the Btrieve Client Engine version 6.15,
you'll need to place the correct options in the BTI.INI file in
your \windows directory. Note that with the 6.15 engine, the
meaning of the /t parameter has changed. You will now use the
/t parameter to specify the maximum number of transactions,
and this number must be greater than zero (15 is the default).
The transaction file name is always BTRIEVE.TRN, but you
will need to specify a directory location for the transaction file
on the trnfile= line below the options= line.
Disregard what the Access BTRIEVE.TXT file says
about where to put transaction files. In a multi-user, non-clientserver environment, each Btrieve Client Engine requires its own
transaction control file, so make sure that this file is in its own
directory for each installation of the client engine.
If you're using NetWare Btrieve NLM, these options
are set in the BSTART.NCF file on the server, using the
BSETUP program. The NLM always uses the transaction
control file BTRIEVE.TRN in the NetWare system directory,
but you must specify a maximum number of open transactions
greater than zero.
Other parameters can cause problems as well. For
instance, if your Btrieve configuration lacks a /u parameter, and
you have data in Btrieve files which use Btrieve data
compression, you wont get the Invalid options message, but
you will get Unexpected error from external database driver
[58] when you try to read a compressed record.
Finally, this error is prone to appear quite suddenly in
an application that used to work. It usually manifests itself right
after youve installed some other piece of software that uses
Btrieve. Its smart to check your [btrieve] options line after
installing anything Btrieve-related, to make sure the installation
hasnt shot your hard-won Access parameters in the foot.
Access opened my DDF, but I still dont see any tables in it.
Either there are no tables in your DDF, or transaction
processing is not enabled. If youre running the Btrieve NLM,
chances are that Btrieve transaction processing is disabled at the
NetWare server. Youll need to LOAD BSETUP, the NetWare
Btrieve setup utility, either at the NetWare server console, or at
a workstation running the RCONSOLE utility. Use this setup
program to increase the Number of Transactions parameter.
This parameter sets the maximum number of clients which may
have transactions open on the server at any given time. The
default value for this parameter is 15, but must be greater than
zero in order for Access to attach to server-based Btrieve files.
When I use Access to try to attach my Btrieve version 6.x
tables, I get the error message: Disk or Network Error.
Youre trying to open a Btrieve version 6.x file with a
Btrieve for Windows version 5.x driver. Btrieve returns a status
code of 2, which Access interprets and reports as a disk or
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
network error. In order to open a Btrieve version 6.x file, you
must have a Btrieve for Windows version 6.x engine. You
wont be able to open a Btrieve version 6.x file on a local hard
disk without the Btrieve for Windows version 6.15 Client
Engine, and in order to open a version 6.x file on a NetWare
server, youll need to be running version 6 of the Btrieve NLM,
and attaching to the file using the client/server Btrieve for
Windows DLLs and BREQUEST.EXE. Btrieve version 6.x, on
the other hand, will read and write Btrieve version 5.x format
files.
Can Access work with Btrieve files through the Btrieve VAP?
Yes. If youre using a version of NetWare Btrieve
implemented as a VAP, Access will attach to this data. Set up
Btrieve in exactly the same way you would when using the
NLM version of NetWare Btrieve, with BREQUEST.EXE
running underneath Windows and the NetWare requester DPMI
library WBTRCALL.DLL, and Access will never know it isnt
dealing with the NLM.
When I export a table to Btrieve file, Access creates an
additional primary index field called M_I_C_R_O_S_O_F_T
even when I have a primary key defined in the Access table.
Is there a way to disable creation of this 4-byte index field?
This field is created whenever Access has to create a
DDF definition for the file. The field is necessary because of
some assumptions that Access has to make about the data. First
it initializes enough records to hold the data, and then attaches
to it and modifies the fields. If you attach to a table in a DDF
file that has already been defined and simply modify the data
that it refers to, Access will not create this field.
I finally got Access to attach my Btrieve files. But some
queries are unbelievably slow. Whats going on?
Access is a relational database front-end, which is built
upon and which enforces the constraints of a database language
called SQL. Because Btrieve does not enforce SQL relational
database structure on its data unless the data was created using
Scalable SQL, Access is limited in the assumptions it can make
about the file structure. It's safest to make no assumptions, and
for any given SQL query, to perform a complete file scan,
matching the records returned with the query criteria. Not only
is this the safest approach, its also the slowest. The native
Access driver for Btrieve seems to be willing to make use of
indexes to optimize its queries, but it will not use manual or null
indexes, indexes which employ an alternate collating sequence,
or indexes which have any segments which do not correspond to
complete fields. And, naturally, any query which selects records
based on fields which are not indexed will require a complete
file scan. Access 1.0 documentation seemed to imply that
segmented indexes on non-contiguous fields were not supported,
either, though this may not be true of Access 2.0.
The way in which Access interprets a query will also
affect performance. Though SQL dictates the query syntax, it
does not stipulate how a query is to be implemented by the
database engine. The only control the user has over Access, in
terms of how records are to be retrieved, is at the SQL level
with the definition of the query. ²
BTRIEVE TECHNOLOGIES
TECHNICAL CORNER
OCTOBER-DECEMBER, 1994
SUPPLEMENT TO B TRIEVE DEVELOPER'S JOURNAL
MAD'S COLUMN
Hello and welcome to the fall issue of
Btrieve Technologies Tech-Corner.
It was exciting and interesting to see
and meet with everyone at THE SUMMIT. It
had been awhile since I had the opportunity
to meet with many of you. And I appreciate
the time that everyone took out of their
excessively busy schedules to meet with us.
We received a lot of information from
you directly on what product features
(support for greater than 4GB files, nested
transactions), utilities (more complex and
user friendly), and drivers (native ODBC)
you need to maintain your competitive
edge. The exposure of our Microkernel
Database architecture helped many of you
understand BTIs positioning in the dynamic
world of databases.
It was good to hear, as several of you
left the Q&A Session on Tuesday, that you
are now confident that Btrieve Technologies
is alive, creating new products, adding key
new features and looking towards the
future.
One request: Ive placed on
CompuServe a purposefully short survey
with features that you would be willing to
pay for in a billable support program. We
are currently amassing that information to
create programs that fit our customers
needs. If you were unable to attend The
Summit, Id appreciate your response. We
have not formally defined any programs yet
and await your input. We hope to have
these programs in place by early to midyear
1995.
Wishing you a Happy, Healthy and Terrific
start of the new year.
Happy Programming!!
Mad Poarch
Vice President, Customer Service
TECHNICAL Q&A - BTRIEVE V6 OPTIMIZATION
What are the issues involved in fine
tuning a Microkernel NLM?
To fine tune the Microkernel
engine, both the hardware and the NLM
configuration should be examined. It is
recommended that any Database Server
be at least a 486 66/MHZ machine and
that it be dedicated to providing
database services.
The Microkernel NLM configuration
options can affect performance.
Unfortunately, it is difficult to make a
blanket statement that will guarantee
improved or optimal performance. In
the answers to each of the questions
below, we have tried to cover common
aspects of how performance can be
affected by the NLM configuration, as
well as other platform considerations.
Can page size affect the way the
Microkernel performs?
When choosing a page size for a
file there are issues involved that can
affect performance. Using a page size
that is an even increment of 512 (1024,
2048, 3072, 4096) is suggested. In the
NetWare environment, blocks are
usually read in even increments of 512.
If you specify a page size other than
those listed here, NetWare may read
two blocks for a single page read.
There are at least 3 ways in which
to determine page size. The first is to
utilize disk space, to put as many
records on the page with the least
amount of wasted space. The second is
to put only one record on a page. The
third is to place as many records on a
page as possible. All three scenarios
have their pros and cons, and
depending upon the usage of the system
can affect performance.
When multiple records are on a
page, chances increase as the file is
used that the Microkernel engine will be
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
holding the page requested in cache,
thereby reducing the number of disk hits
necessary to read records. However, if
the data set being read is very select and
predictable, then the Microkernel
engine may be managing pages that will
never be fully used. In that case, the
fewer records per page the better.
Having fewer records per page is
also useful when using Concurrent
Transactions. Page locks are used to
determine concurrency in a Concurrent
Transaction. Fewer records on a page
reduces the amount of page lock
contention that may occur in this type of
transaction.
I am trying to perform transactions in
the NetWare environment. What
settings do I need, and should the files
be flagged Transactional?
In order to perform transactions
(Concurrent or Exclusive), the
Microkernel Engine will have to be
configured to support transactions. The
Number of Transactions value will need
to be set. For the NLM this is typically
set to the same value as the Number of
Remote Sessions. When a Microkernel
Transaction is initiated from an
application, any server that the
workstation is attached to AND which
has the Microkernel engine loaded on
it, MUST be configured for transactions.
Flagging the file Transactional will
not invoke TTS. The Microkernel Engine
IN THIS ISSUE
Technical Q&A: Btrieve Optimization...17
The Future of the Microkernel................19
Technical Insights..................................22
(NLM) uses the flag to indicate that all
operations should be treated as single
system transactions. The Microkernel
Engine has an internal system
transaction. A system transaction can be
composed of several Microkernel
operations. When the system
transaction is synched all the
operations are committed to the
operating system. The TTS flag tells the
Microkernel engine to treat a single
operation on the file as a system
transaction. Flagging files as
transactional will cause performance to
decrease because of the inefficiency of
treating each operation as a system
transaction. The trade off is tighter data
integrity.
For the workstation products (DOS
and Windows) there is an /e option that
provides transaction durability. When
the application receives a status of 0 on
operation 20 (End Transaction) and the
/e option is in use, this means that the
system transaction has synched and the
transaction is committed to the
operating system.
Accelerated mode in the 5.x engines
allowed for quick cache access to files.
Does 6.15 have the same capability?
Accelerated mode implies that the
integrity of the file is not essential to the
state of the system, and that the file will
be accessed in the quickest way
possible. In the 5.x engine this was
done by terminating pre-imaging and
relying on caching for Microkernel
operations. With the 6.15 engine and
6.x files, pre-imaging is no longer used
and system transactions provide for
caching of operations.
In essence, accelerated mode and
normal mode are one and the same,
without the implication that data
integrity is a low priority. If it makes
sense to open the file in accelerated
mode, developers should continue to
use the setting. In the future accelerated
mode may reappear.
Why does the conventional memory
footprint for Btrieve for DOS 6.15 vary
depending upon the memory manager?
The footprint can vary because of
the protected mode stub that is loaded
with Btrieve. Depending on how a
memory manager is configured, the stub
will have to make different real mode
memory allowances.
14
Btrieve Technologies technical
support staff has a 3 page white paper
on different configurations and memory
consumption results.
Because real mode memory
consumption is such an important issue,
Btrieve Technologies has taken a hard
look at how much memory the
Microkernel engine is using during the
load process and once it is resident.
Btrieve Technologies has a Btrieve for
DOS update that is available to all
registered users. We have been able to
trim conventional memory consumption
by about 20K in some instances.
The 5.x engines had a maximum cache
size of 64K. Why do the new engines
have a default size of 512K?
The new engines require more
cache due to the nature of how the
Microkernel Engines background writer
works. In essence, the new engine relies
heavily on pages being present in cache
to cut down on disk accesses. For both
the DOS and Windows engines, the
cache is allocated in upper memory
areas. That is why the system
requirement for RAM has been
expanded. The use of a larger cache
provides for faster performance and
more efficient use of memory.
Allocating too small of a cache for
the Microkernel engine can affect its
performance in any environment. The
optimal setting is to minimize disk hits
and maximize cache hits. Once a page
is read by the Microkernel engine, the
optimal configuration would be to never
have the engine reread the page.
Default settings for this parameter are
generally sufficient. However, if there is
memory flexibility in your system, give
the engine more cache. Giving the
Microkernel engine too much memory
will not degrade performance.
Which Microkernel parameters affect
performance?
See the table at the top of the page
opposite, outlining parameters that do
not directly affect performance and
those that do. Options marked with an
asterisk (*) are documented in the online help files that come with the 6.15
version of the Microkernel engine.
WHOS WHO AT BTRIEVE TECHNOLOGIES
Doris Eldridge
Acting Director of
Development
Doris primary responsibilities include
coordinating the releases of all of
Btrieve Technologies software
products. She works with developers,
QA engineers, and technical writers to
define schedules, resolve technical
issues, and set priorities. Other
responsibilities include supporting beta
sites, reviewing documentation, and
assisting in testing software. As acting
head of development, Doris also
interacts with other departments such as
marketing, sales, and services to
coordinate project work, and also
handles the administrative issues for the
department.
Doris joined Btrieve Technologies, Inc.
as a founding team member in April of
1994. Prior to that, she worked as a
software engineer at SoftCraft, Inc. for
approximately six months, shortly
before the company was acquired by
Novell, Inc. She worked in the Database
Products development group for Novell,
first as a software engineer, and then
engineering lead for the NetWare SQL
product, from the time of the acquisition
until the group was sold to Btrieve
Technologies, Inc. In August, 1993, she
assumed responsibility for the Quality
Assurance group for the Austin division
of Novell.
Away from the office, Doris, her
husband, Larry, and their two girls,
Jennifer, 14, and Nicole, 9, enjoy
spending time at their weekend place in
the country, a short hours drive from
Austin. Favorite vacation spots include
South Padre Island, Texas and Estes
Park, Colorado. Doris also enjoys
playing softball in a recreational softball
league with her coworkers and friends.
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
Why is Btrieve for DOS 6.15 slower
than Btrieve for DOS 5.10a?
Before the release of Btrieve for
DOS 6.15, several of our beta
customers reported the improved
performance of inserts, updates, and
deletes. We were all concerned when
customers reported decreased
performance of reads with the released
product. Through customer test cases
and development efforts we have been
able to improve the Btrieve for DOS
6.15 engines performance. Engineering
was able to identify a performance
degradation when switching from real
to protected mode.
Changes have been made to
eliminate the degradation. These
engineering changes are in the Btrieve
for DOS 6.15.1 update. Users that were
registered by October 24th, 1994 will
receive the update in the US mail. The
update has been made available on
CompuServe in the BTRIEVE forum. The
forum has special instructions for
obtaining the update.
How can the system be monitored to
insure that it is configured properly?
The Microkernel Engine returns
appropriate status codes for
configuration problems. For instance, if
there are not enough file handles
configured, then applications will
receive a status of 87. If there is not
enough memory specified by the cache
allocation parameter, a status 100 will
be returned. Most Btrieve status codes
provide specific information regarding
what has occurred to create a non-zero
status code.
All server versions of the
Microkernel Engine will provide a
monitoring utility. In the NetWare
environment this utility is BTRMON
DO NOT AFFECT PERFORMANCE
DO AFFECT PERFORMANCE
Number of Open Files
Number of Handles
Number of Locks
Number of Transactions
Largest Compressed Record Size
Largest Page Size
Number of Remote Sessions
Cache Allocation
Perform Index Balancing
Logging of Selected Files
Create Files in Pre-v6 Format
Create Files as Transactional (NLM)
Transaction Durability *
Transaction Bundling *
NLM. System configuration can be
monitored and resource usage can be
verified through the monitoring
facilities.
If there are two applications that
require the Microkernel Engine, what
settings should be used?
It is always possible that two
applications that require the
Microkernel Engine require different
settings. For example, some applications
may require transactions while others
do not, or some may require an
extensive number of file handles.
The best rule of thumb is to adjust
to the highest settings, and leave settings
alone that enable specific functionality.
For instance, if compression is set, leave
it set. If your application does not
require compression it will have no
affect on your application, however by
changing it another application may
break. Again, if a configuration is set
improperly, the application will receive
an appropriate status code indicating
the problem.
Typically, I use BUTIL.EXE to create my
files. Every time I try to create my files
with BUTIL 6.15 I receive a status code
of 97. What is causing the 97?
The status 97 indicates that
BREQUEST needs a larger /d parameter
and that the Microkernel Engine also
needs to be configured with a matching
value. In this case BUTIL version 6.15 is
setting the data buffer length to 33K.
Consequently, the Microkernel Engine
(NLM) and the /d for BREQUEST need
to be set to 35000. The other alternative
is to continue using BUTIL version 5.12.
What is the TIMER value in the
BTI.CFG file?
Btrieve for DOS version 6.15 is
architected to include a foreground and
a background task. In a single tasking
OS, such as DOS, task switching is not
available, but it can be simulated. The
Microkernel engine for DOS
accomplishes this by hooking into the
timer interrupt to simulate task
switching. In some configurations, other
applications may also use the timer
interrupt.
If these applications are not wellbehaved, the system may hang when
multiple applications attempt to
interface with the timer interrupt. The
timer entry is used to disable Btrieves
use of the DOS timer interrupt. By
default, this entry should always be set
to Yes. You may need to disable the
timer if you experience system hangs or
abends while running your Btrieve
applications.
FUTURE OF THE MICROKERNEL
EVOLUTION OF THE MICROKERNEL
DATABASE ENGINE
Since its introduction in 1982,
Btrieve database technology is now in
its sixth generation. Changes over the
years have included increased
functionality, network support, clientserver capability, and support for an
ever increasing number of platforms and
languages. Three central philosophies
have driven the technology
development of these products: Make
efficient use of hardware and operating
system resources, maintain the integrity
of data, and maintain a consistent
interface.
The fact that Btrieve was
originally designed for the PC gives it a
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
great technological advantage over
systems which have been scaled down
and adapted from mainframe and
microcomputer implementations to run
on stand-alone and network systems.
This can be seen in a quick comparison
of the sizes and relative speeds of other
database engines.
Btrieve has long been
recognized for its performance, but
DATA MODEL DEPENDENT
ACCESS MODULE FUNCTIONS
Logical functions
Schema (row, column, table...)
Definitional functions
Operations (join...)
Btrieve
Navigational
Model
Scalable
SQL
Relational
Model
Object
Database
Model
Custom
Data
Models
DATA MODEL INDEPENDENT
CORE ENGINE FUNCTIONS
Physical data access
Advanced caching
Data integrity enforcement
Transaction processing
MICROKERNEL DATABASE ENGINE
Microkernel Database Engine Architecture
more importantly for its integrity, as is
evident by the fact that seven of the ten
leading accounting system vendors are
built on the Btrieve database engine.
And as Btrieve has added
features over the years, the API has
remained remarkably consistent. So
consistent, in fact, that applications
written for Btrieve version 1 will still run
on top of Btrieve version 6 without
modification. And this consistency is
also enforced across platforms, allowing
an application to run on a single
computer, or in a client/server
environment on a Novell network,
without any modification.
MICROKERNAL ARCHITECTURE
The release of Btrieve version 6
marks the introduction of the
Microkernel architecture, a new
architectural model for the Btrieve
database products. The DOS and
Windows Btrieve engines have been
completely re-coded from a common C/
C++ code base derived from the
NetWare Btrieve NLM. This code will
form the basis of the platformindependent Microkernel Database
Engine. The Microkernel will handle all
of the core database functions,
Btrieve version 6.5
16
including physical data access,
advanced caching, transaction
processing, and data integrity
enforcement; functions which are
common to all data models.
One of the benefits of this
Microkernel architecture is that it allows
concurrent multiple data model access
to the same data. Because the
Microkernel limits itself to core database
functions, the design is entirely datamodel independent. Currently Btrieve
Technologies has two data model
implementations which use the
Microkernel to provide core services:
the Btrieve navigational model interface,
and the Scalable SQL relational model
interface. Because data integrity is
enforced at the core level, both of these
data access models can be run
simultaneously against the same
physical data.
This architecture also leaves the
door open to new database models such
as an object model interface and tools
to develop custom database models.
Functionality can be added to the
Microkernel to support these models as
they evolve, supporting new types of
applications and information
collaboration. This design will also
improve performance for existing
applications, which will benefit from
new caching and multi-threaded
processing performed by the
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
allocation table (PAT) and index pages.
BTRIEVE NAVIGATIONAL MODEL
INTERFACE
Scalable SQL version 4
Microkernel. And it will be fully
compatible with existing applications,
once again because the basic interface
will remain consistent, though new
features will be added. And finally,
because of the common C/C++ code
base, this architecture will be easily
ported to other platforms. BTI already
has it in place in NetWare, Windows,
and DOS, Windows NT and OS/2 are
both in pre-release.
MICROKERNEL DATABASE E NGINE
FEATURES
In the current release, the
Microkernel includes features to support
record set operations, otherwise referred
to as extended operations. This includes
the capability to do partial record
retrieval and record filtering. Huge
record support is implemented at this
level as well through chunk operations,
effectively removing any limits to
individual record size. Percentage
operations, which indicate how far you
are along a given index path are also
supported in the current release, and
they are useful not only in GUI
applications for determining thumb
scroll positioning, but they are also one
of the tools which will enable true costbased optimization in future releases of
Scalable SQL.
The current Microkernel engine
enforces data integrity constraints. If
your database is defined using Scalable
SQL to enforce relational integrity, that
is enforced at the Microkernel level, so
that an application accessing that data
using another database model such as
the Btrieve navigational model will not
be able to violate the relational integrity
of the data. The Microkernel is a true
multi-threaded engine which performs
all of its disk IO in the background. A
complete transaction/isolation manager
eliminates the possibility of dirty reads.
Performance is enhanced by more
efficient internal algorithms, more
efficient caching, and the addition of
symmetric multiprocessing support.
Planned Microkernel features
include transparent two-phase commit,
support for nested transactions which
will be based on the currently
implemented concurrent transaction
support, capacity for files larger than
4GB, improved continuous operation
support which is not dependent upon
sparse files, eliminating the potential for
file corruption in the event of a system
failure during continuous operation and
allowing cross-platform support for
continuous operation on platforms
which do not implement sparse files.
Future versions of the Microkernel will
support specialized data and key types,
particularly array keys, message/full-text
indexing, and object store. A scripting
language for stored procedures and
event triggers will be implemented at
the Microkernel level, and core data
management functions will also include
support for database replication and
versioning. Versioning will allow the
Microkernel to maintain a database in a
static state based upon the assignment
of a version, while still allowing updates
to the files which will not affect the
versioned data.
Planned performance
enhancements for the next version
include IPX requesters, persistent
caching across file opens and closes,
and a consolidated log file. Future
version releases will implement readahead caching, including a requester
cache, self-tuning parameters, and
cache weighting , especially of page
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
Btrieve version 6 is shipping
currently as an NLM, and as a client
engine in Windows and extended DOS.
Versions for OS/2 and Windows NT are
currently in pre-release.
Btrieve 6.5, scheduled to begin
shipping during the second quarter of
the coming year, will feature triggers
and stored procedures, improved
performance, support for nested
transactions, support for huge files, and
transparent two-phase commit.
Enhanced log capabilities will include
single, durable log file maintained by a
separate thread, providing better
performance. The Windows and
Windows NT drivers will feature a DLLonly requester.
SCALABLE SQL RELATIONAL MODEL
INTERFACE
Relational APIs will include the
native Scalable SQL API and ODBC.
ODBC support is currently provided by
Microsoft and Q+E\Intersolv. BTI is
currently considering whether or not to
provide direct ODBC support.
SQL syntax in future versions
will continue to support Scalable SQL
v3.x syntax. Future versions will add
compliance with the at least level 1 of
the SQL 92 standard, and will add
support for SQL3 level syntax with
triggers, assertions, control statements,
and selected other syntax additions.
Scalable SQL 3 is currently
shipping as an NLM, and as a Windows
client engine. The extended DOS client
engine is currently in beta.
Scalable SQL 4 is slated to
begin shipping in the coming year. New
features will include full cost-based
optimization using the Microkernel
percentage operations in its cost
analysis algorithms. It will also add
support for SQL3 level syntax, and will
include a scripting language for
implementing event triggers and stored
procedures at the Microkernel level.
Plans are to add platform support on
OS/2 and Windows NT with the version
4 release.
TECHNICAL INSIGHTS
Btrieve for DOS v6.15.1 Update
Below is a description of the critical problems
that are fixed in the Btrieve for DOS v6.15.1
product update, which began shipping to
registered owners of Btrieve for DOS v6.15
Developers Kit and Client Engine in November.
If an error is returned on a Btrieve INSERT,
UPDATE or DELETE operation and the
application then continues to insert records
without closing the file, the size of the Btrieve file
can become very large.
Under some conditions, the performance of
the read operations in Btrieve for DOS v6.15 is
worse than with Btrieve for DOS v5.10a.
If a Btrieve file has an owner name with
encryption enabled, performing a massive insert
will cause unexpected errors or the machine
may lockup.
You can now access Btrieve files that are
located on CD-ROMs. Previously, status 12 was
returned when you attempted to access a file on
a CD-ROM drive.
When the first workstation issued a GET FIRST
with a 200 bias, it did not release the lock
following an update operation.
You can now specify the location of the
Btrieve transaction file (BTRIEVE.TRN) on the
command line using the /t option. The format
for the /t option is as follows:
/t:[number of transactions]:[transaction file]
You can specify either the number of
transactions, or the transaction file name, or
both. If both are specified, then the number of
transactions must be specified first. If either
value is omitted on the command line, then the
value in the configuration file (BTI.CFG) applies.
If your application does not use transactions and
you want to disable the Microkernel from
opening the transaction file, you can specify the
following:
/t:0:nul
Earlier versions of Btrieve v6.x removed the
ability to create a segmented index that
overlapped with an AUTOINC key. This was
available in Btrieve v5.x. It has been restored
with this patch update. Btrieve allows the
segmented key to overlap the AUTOINC key
only if the key number of the AUTOINC key is
less than the key number of the segmented key.
You can now load Btrieve for DOS in high
memory, reducing the conventional memory
footprint size. Some conventional memory will
still be used for the DOS/4G interface. The
amount of memory used depends on the
memory manager configuration that you have
installed.
Also the amount of memory available for the
largest executable program is increased by about
20K bytes, as a result of better memory
management by the Microkernel loader.
You may still experience problems when
18
attempting to unload Btrieve, if it is loaded in
high memory. This could be due to the
combinations of other programs that are also
loaded high. If you experience such a problem,
you will not be able to load Btrieve in high
memory.
Under some conditions, executing a BUTIL STOP command caused the workstation to hang.
This problem has been fixed.
Scalable SQL Generates Microkernel
Status 21
Status 62 on Update Chunk
Btrieve 6.1x
Scalable SQL for Windows 3.01
When using the local Scalable SQL for Windows
engine and the Client/Server Microkernel engine,
a status 21 Key Buffer Parameter is Too Short
will be returned for any query that requires a
temporary sort file to be built. This error does
not occur when using the Client/Server Scalable
SQL engine, or the local Scalable SQL for
Windows engine with the local Microkernel
engine.
If the Microkernel configuration specifies both
local and server access, and the Scalable SQL
temporary sort file directory is specified as a
directory on the local drive, queries that require
temporary sort files can be run against the local
Scalable SQL engine. With this configuration, all
files located on the server will be handled by the
requester, and temporary sort files will be built
on the local drive by the local Microkernel
engine.
This configuration may provide performance
improvements since the data being transferred to
and from the temporary sort file will not have to
be re-transferred over the network. However,
this configuration does require that the
workstation have sufficient memory for the local
and requester Microkernel components along
with the Scalable SQL local engine. The
workstation must also have sufficient disk space
to store the temporary sort files. The size of these
files will depend on the amount of data satisfying
the query.
BREQUEST.EXE Memory Usage
NetWare Btrieve 6.1x
The amount of conventional memory used by
Brequest v6.1x varies slightly depending on the
version, and the directory from where it was
loaded. However, the latest version of Brequest,
v6.16, takes 384 bytes less memory than
Brequest v6.10e.
For example, loading Brequest with default
parameters from the C:\ directory produces the
following results:
6.10e
34320 bytes
6.15
33488 bytes
6.16
33936 bytes
Loading from different directories may produce
slightly different results - longer paths will
increase the memory usage by a multiple of 16
bytes. For example, loading from the network
directory AUS-TIN\BRO:W\LANDERSO\DOCS
produces the following results (an additional 32
bytes for each version):
6.10e
34352 bytes
6.15
33520 bytes
6.16
33968 bytes
The increased memory usage due to the longer
path is caused by the allocation of a copy of the
environment plus the programs filespec by
DOS when the TSR loads, and not something
specifically allocated by Brequest.exe.
A status 62 (incorrect descriptor) can incorrectly
be returned on an Update Chunk operation,
specifically a RANDOM, INDIRECT operation.
This occurs in the Btrieve for Windows engine
6.15.1 and the Btrieve for Windows requester
6.15.1.
The problem occurs because Btrieve is verifying
that the structure used to describe the operation
does not lie in the memory area that is holding
the data that will be used to update the data. So
the descriptor would look like:
Descriptor.dwSubFunction =
INDIRECT_RANDOM_CHUNK_SUBFN;
Descriptor.dwNumChunks = 1L;
Descriptor.dwChunkOffset =15;
Descriptor.dwChunkLen = 0x1000;
Descriptor.lpChunkData = lpMemBuf;
wDataBufLen = sizeof(Descriptor);
When Btrieve gets the call, it has the address of
Descriptor, being 241F:0234 for example.
Then it looks at the value in
Descriptor.lpChunkData, being 1F49:0000 for
example. It then takes the length specified by
Descriptor.dwChunkLen and adds it to the
address of Descriptor.lpChunkData, so 0x1F49
+ 0x1000 = 2F49. Because 2F49 falls below
the Descriptor address Btrieve assumes that the
actual Descriptor is in the memory area that will
be used to update the file, thereby causing a 62.
However, because this is the Windows
environment, the two pointers specified by
Descriptor and Descriptor.lpChunkData are not
related so using pointer arithmatic as described
above does not work. The pointer values are
selectors, therefore if the two pointers do not
have the same selector value (241F for
Descriptor and 1F49 for lpChunkData) they are
not in the same memory area. The usage above
would apply if they were segments. The solution
is to allocate the descriptor with the data
segment:
hMemBuf=GlobalAlloc(GMEM_MOVEABLE,
(DWORD) (BUFFER_LEN +
Sizeof(Descriptor) +
sizeof(TEST_RECORD));
lpMemBuf=(LPBYTE)GlobalLock(hMemBuf));
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
Btrieve File Corruption
Btrieve for DOS 5.10a
When investigating a case of Btrieve file
corruption, there are four general causes. More
than 90% of all Btrieve file corruption cases are
caused be problems in categories III and IV.
I. File corruption is being caused by a problem
with the Btrieve engine. If this is the case, the
corruption should be reproducible. To isolate
Btrieve as the cause, you must provide
Developer Support with a test case that
demonstrates the problem. This test case can be
either your application, or a test application
based on the code in your normal application.
Btrieve cannot be identified as the cause without
a test case. Btrieve logging and the Rollforward
utility can also be utilized when trying to
produce a test case. Similarly, in the Btrieve 6.x
NLM environment, the BRECORD utility can be
used. Always make sure you are running the
latest version of Btrieve with any available
patches applied. Patches can be downloaded
from CompuServe, or you can contact
Developer Support and request that the patches
be mailed to you on diskette. If Btrieve is found
to cause the file corruption, the problem will
only be fixed in the current or next version of
Btrieve. Development will not fix older versions
that are no longer shipping.
II. File corruption is being caused by the
application. If the application can make Btrieve
calls successfully, but data returned by Btrieve is
corrupted, or if the workstation hangs, the cause
can usually be found in the application.
Common causes include overwritten data
buffers, position blocks or memory in general.
Utilities such as POSCHECK can help track
down some of these errors. Various Btrieve
debugging utilities are available for download
from Compuserve, or you can contact Developer
Support and request that the utilities be mailed to
you on diskette.
III. File corruption is being caused by hardware
incompatibility or malfunction. Check all the
workstation and server hardware. Hardwarerelated causes can be difficult to isolate, and
sometimes may require you to swap
components. If the cause can be proven to stem
from one particular workstation, it is usually
hardware related. When running a NetWare
LAN, always make sure server hardware,
workstations, LAN cards and any other
components are NetWare-certified.
IV. File corruption is resulting from interaction
with another software component, including
other TSRs, memory managers or device drivers
at the workstation, as well as LAN card drivers
and other NLMs at the server. Remove all
unnecessary components and see if the problem
persists. If not, add the components back in one
at a time to see which one may be causing the
conflict. Also, make sure that each component is
the current version and is NetWare-certified for
the NetWare version running on the server.
The best approach to take when investigating
Btrieve file corruption is isolate and reproduce.
Always make sure you start your tests with
clean files by rebuilding any files that produced
an error during your investigation.
Universal Naming Convention (UNC)
and BREQUEST
BREQUEST 6.10e, 6.15, 6.16
UNC is not supported with BREQUEST.EXE. A
status 12 (file not found) will be returned if the
Universal Naming Convention (UNC) is used to
qualify a file path on a Btrieve OPEN operation
when using BREQUEST.EXE.
For example, an OPEN request for the file \\AUSTIN\BRO\OS2\LHEATER\TEST\PATAPP.DTA
will return a status of 12. Do not use the
Univeral Naming Convention (UNC) to specify
SERVER/VOLUME with BREQUEST.EXE.
If Server/Volume must be specified, then
SERVER/VOL:\path is the correct way to specify
the name of the path. This is considered to be
NetWares convention for file specification.
Opening Files on a CD-ROM Drive
Btrieve for DOS v6.15.1
Btrieve for DOS v6.15.1 will let you open a
Btrieve file on the local CD-ROM. However,
there are some issues to be aware of:
A CD-ROM drive is handled as a network drive.
The default file sharing mode on a network drive
is MEFS (multi-engine file sharing). Since the CDROM is a read-only device, Btrieve cannot create
the lock file when it tries to open the Btrieve file.
Status 81 (lock error) is returned in this situation.
You can avoid this error in the following ways: 1.
Open the file with the SEFS (single-engine file
sharing) bias. 2. Specify SEFS for remote files in
BTI.CFG file. 3. If MEFS is specified, redirect the
lock file using the /i option to a different drive.
Loading BREQUEST.EXE High
NetWare Btrieve NLM 6.10
When BREQUEST.EXE v6.10x is loaded into
memory, the transient portion of the TSR
requires a maximum of 173KB. The only
memory areas below one MB with enough
space to accommodate this driver are the
conventional memory area and the Upper
Memory Block (UMB). Therefore, when
BREQUEST.EXE is loaded high, it will be placed
in the UMB if space is available. After the TSR
has loaded, the resident portion occupies 34KB.
BREQUEST.EXE can only be loaded high if the
IPX (IPX.COM or IPXODI.COM) driver has been
loaded first. NETX can be loaded either before or
after Brequest is loaded. If an attempt is made to
load BREQUEST.EXE high after IPX and NETX
have been loaded high, the system may either
hang or return an 80386 Processor Exception
error if there is not enough available memory.
BREQUEST.EXE can also be loaded in base
memory with the drivers loaded high.
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
Scalable SQL Programmers Manual
Documentation Error
There is a reference to the Getting Started
manual in the Scalable SQL for Windows
Programmers manual in the last paragraph on
p4-28. This should refer to Chapter 3 (Query
Optimization) in the Scalable SQL Reference
Manual.
Redirecting Pre-Image and LCK Files on
NetWare
Btrieve for DOS
In a single-volume NetWare environment,
Btrieve pre-image files for 5.x format files, and
LCK files used by Btrieve v6.15 in MEFS
(MultiEngine File Sharing) mode can be redirected to a map root drive to avoid giving users
CREATE rights in the directory containing the
Btrieve data files.
When using a client version of Btrieve (Btrieve
for DOS, OS/2 or Windows) in a NetWare
environment, administrators may want to
configure NetWare so that users have rights to
read and write to the directory containing the
Btrieve data files, but not create new files in that
directory. However, without Create rights,
Btrieve cannot access the data files, since it
cannot create the pre-image files used when
accessing Btrieve files in the 5.x format, or the
lock file needed for MEFS.
By default, Btrieve creates the pre-image files in
the same directory as the Btrieve data files.
Btrieve can be configured to redirect the preimage and lock files to a different drive with the /
i: option, for example:
Btrieve /m:38 /p:4096 /e /i:G
This configuration tells Btrieve for DOS to create
the pre-image and lock files on drive G
(whatever that might be mapped to). Drive G
must have the same directory structure as the
drive with the Btrieve files. For example, if the
Btrieve file FILE1.BTR is in the directory
F:\APPL\DATA, the pre-image file FILE1.PRE will
be created in the directory G:\APPL\DATA.
Since all users must share the same pre-image
files, everyone must use the same redirection
path and a local drive cannot be used. One
solution is to set up the matching directory
structure on a different volume, and map the G:
drive to that volume. In an environment where
the server only has one volume, the only way to
set up a separate directory for pre-imaging where
users will have Create rights is to use the MAP
ROOT command. For example, if the Btrieve
data files are in the directory F:\APPL\DATA,
another directory can be set up like
\PRE\APPL\DATA where users are given Create
rights. Then, issuing the command: MAP ROOT
G:=\PRE will set up a map root drive that can be
used in the Btrieve command shown above. The
pre-image files will be successfully redirected to
the \PRE\APPL\DATA directory instead of the
\APPL\DATA directory.
Set Directory Operation Will Not Cross
Drives
NetWare Btrieve NLM 6.10
The Btrieve Set Directory (17) operation does not
change the directory if a path on a different drive
is specified. For example, if the current working
directory is F:\APPL, and a null-terminated
KeyBuffer of G:\DATA is passed to the
SetDirectory operation, a status 0 is returned but
the directory is not changed. This result occurs
even if F: and G: are mapped to the same server
and volume. Subsequent attempts to open a file
that is located in G:\DATA returns a status 12
(File Not Found).
If the Set Directory operation is given a path that
is on the same drive as the current working
directory, such as F:\BTRDATA, it works
correctly.
This problem exists with BTRIEVE.NLM v6.10c,
and all 5.10x versions of client-based Btrieve for
DOS, OS/2 and Windows.
If the Btrieve files to be accessed reside on a
different drive than the current working
directory, the drive and path along with the file
name can be specified in the Open operation
instead of using the Set Directory operation.
The problem does NOT exist in the v6.15
Btrieve for Windows client.
Scalable SQL for Windows Registration
If someone purchases both a Single-User copy
and the Unlimited License copy of Scalable SQL,
and attempts to install them in the same place
(such as C:\BTI), the registration program will not
run for the second installation. The files installed
by these two products are identical; the products
only differ by the license. The single-user engine
is not crippled in any way. So, the double
installation wont cause you to lose any files,
but the registration program thinks its already
been run, and does not run again.
To complete the registration for the product
being installed second, just re-install it in a
different directory so that the registration
program will run.
Phantom Users in BTRMON
Btrieve 6.10
When a Btrieve application is running, a users
name is displayed in the monitor utilities when
querying about user information. If a user has
been logged out from the file server with the SPX
session still intact, no user name appears in the
monitors user name list. The space for the
userss name is filled with blanks.
Btrieve itself does not keep track of user names,
only network addresses. It is the monitor utility
(BTRMON) that is querying the bindery to find
the user name information. So Btrieve is not
aware that a particular user is associated or NOT
associated to the address it is talking to.
20
Case Insensitive Ordering with
NetWare SQL
CURRENT VERSIONS
NetWare SQL 3.00
Case-insensitive sorting of string fields (i.e.
SMITH is sorted the same as Smith) is
accomplished in NetWare SQL by creating an
index on the table with the CASE attribute
specified for the field. For example, CREATE
INDEX NameSort ON Patients (Last^Name
CASE). Subsequently, SELECT * FROM Patients
ORDER BY Last^Name will use this index and
return the data sorted without regard to case.
If no index exists for the fields specified in the
ORDER BY clause, NetWare SQL creates a
temporary sort file to achieve the proper
ordering. Here, there is no way to specify that
the temporary sort file be built with caseinsensitivity. So, the application must first create
the index with the CASE attribute, and then issue
the select statement.
In some cases, this procedure is not possible; for
example, in a joined view where the ORDER BY
fields are not all from the primary table, there is
no way to create such an index. In this case, the
application could create a temporary file with the
appropriate index, insert the selected records into
this table, and then read the data from the
temporary table using its index.
Another alternative is to use the Relational
Primitive functions. The xOrder primitive allows
the CASE attribute to be specified for sorting the
view; this applies to both existing indexes and
temporary sort files.
Get Previous After Inserting Duplicate
Key Values
Btrieve Data Management Products
Btrieve Engine for DOS....................6.15.1
Btrieve Developer Kit for DOS.........6.15.1
Requester for DOS..............................6.16
Btrieve Engine for Windows.............6.15.1
Btrieve Developer Kit for Windows..6.15.1
Requester for Windows...................6.15.1
Btrieve Developer Kit for OS/2............5.10
Btrieve for NetWare NLM.................6.10c
DOS BREQUEST............................6.10e
Windows WBTRCALL.DLL.............6.10b
OS/2 BTRCALLS.DLL.......................6.10b
Scalable SQL Relational Data
Management Products
Scalable SQL for Windows.................3.01
Scalable SQL Developer Kit for
Windows...........................3.01
Requester for Windows......................3.01
Scalable SQL for NetWare
(Server Edition).....................3.01
Requesters: DOS SQLREQ.EXE....3.01
SQLREQS.EXE...3.01
Win WXQLCALL......3.01
OS/2 XQLCALLS........3.01
XQL for DOS....................................2.11b
XQL for OS/2......................................2.11
Query and Reporting Tools
Btrieve 5.x
A GetPrevious (opcode 7) operation immediately
after inserting a record with a duplicate key value
should return the previous duplicate. However,
under Btrieve v5.10, the record with a smaller
key value is returned instead.
For example, if a file has two records with key
values AAA and BBB and then three records are
inserted with the same key value of CCC, a
GetPrevious operation after the third insert
should return the record with the second
instance of key value CCC. Btrieve for DOS
v5.10a returns the record with key value BBB
instead.
The correct record is returned on the
GetPrevious operation with Btrieve v6.x. When
using Btrieve v5.10a, a workaround would be to
issue a GetPosition (operation 22) followed by a
GetDirect (operation 23) after the insert and
before the GetPrevious. Then, the GetPrevious
returns the appropriate record.
Xtrieve for DOS................................4.11e
Xtrieve for OS/2................................4.11e
HOW TO REACH BTI
5918 West Courtyard Drive
Suite 400
Austin, Texas 78730
Phone:
(800) 287-4383
(512) 794-1719
Night:
(512) 794-1731
Fax:
(512) 794-1778
CompuServe: GO BTRIEVE
You may also contact Btrieve Technologies via
the Internet. The BTI Internet Domain Name is
btrvtech.com and user names consist of the
persons first initial followed by up to seven
characters of the last name. For example, Mad
Poarchs address is [email protected]
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
marketplace to try to buy Intuit, the makers of Quicken, as well
as take over the electronic cash disbursement and tax filing
systems associated with Intuit. In addition, Microsoft has
aggressively gone after a new relationship with BTI. If
Microsoft thinks this sounds like a good area to be involved
with, you should pay attention - your Btrieve skills may be the
key to your cashing in on the excitement.
1994 - Universal Btrieve Use by ASVs
Btrieve Based
Accounting
By Eric E. Cohen, CPA
In 1994, every major accounting software vendor
(ASV) announced the adoption of Btrieve as their database
manager of choice. In addition, that years spin-off of Btrieve
Technologies from Novell makes the future installation of that
Btrieve-based accounting far more likely on non-Novell
operating system platforms. These changes in the marketplace
make a look at accounting software important for the Btrieve
developer.
This column is the first in a three part series on
Btrieve-based accounting and business information management
software. Over the next three issues, it will introduce accounting
software and peripheral offerings, including low, medium and
high-end selections, and highlight opportunities for developers to
be involved. The second article will concentrate on low end
products and vertical applications, and provide a resource list
for finding out more. The third article in this series will deal
with high end packages, add-ons that augment the softwares
capabilities, and management of practice issues.
Btrieve developers have two primary reasons for
reading this series of columns: to find out about new areas of
opportunity for expanding business (the ASVs are advertising
this ability on your behalf!), and to learn how the new software
offerings can help better manage the developers own
businesses. After all, every business (including yours) has to
keep those books and records for tax time. Developers often
suffer the Shoemakers Children syndrome: internal systems
suffer compared with those done for clients.
There are those two great inevitable events: death and
taxes. Death is limited to twice for humans, according to
Biblicists, and nine times for cats, according to fable. Taxes
come into play at least on an annual basis. What does this have
to do with software?
Microsoft Corporation thinks enough about the
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
Btrieve has been an important offering to accounting
software vendors, as is evidenced by its almost universal
acceptance by the industry. While describing the attributes that
make it so attractive to the readers of this publication is
preaching to the choir, business information systems like
accounting software have been and will be as important to
Btrieve as Btrieve has been to accounting software.
Toward the beginning of microcomputer accounting,
there were COBOL and BASIC, the remains of minicomputer
code brought over to the new microcomputers. Solomon
Software was the eccentric, using MDBS as their database
manager. Then Softcraft offered a new choice: Btrieve.
ASVs who were not hindered by ported minicomputer code
were able to move more quickly to Btrieve. On the high-end of
off-the-shelf products, Great Plains (Great Plains Software, 800456-0025) and Platinum (Platinum Software, 800-999-1809)
were early users of Btrieve. Xtrieve was their readily available
report writer. Macola (Macola, Incorporated, 800-468-0834)
joined the Btrieve bandwagon in 1989. Btrieves speed and
integrity were the greatest reasons Macola and Platinum gained
reputations as worthy replacements to minicomputer-based
software, at a fraction of the cost, with speed and reliability to
match.
RealWorld (RealWorld Corporation, 800-678-6336),
Solomon III and IV (Solomon Software, 800-879-0444), and
ACCPAC Plus (Computer Associates International, Inc., 800225-5224) introduced Btrieve versions over the last two years.
Other high-end accounting holdouts, M*A*S 90 (State of the
Art, Inc., 800-854-3415) and CYMA (Cyma, 800-292-2962),
have announced their future adaptation of Btrieve.
Mr. Cohen is the owner of Cohen Computer
Consulting, an accounting software consultancy in
Rochester NY. He trains CPAs (certified public
accountants) and CAs (chartered accountants Canada) in trends in computer technology and
accounting software. His articles have appeared in
Accounting Today, Audio Microcomputer Report,
Buffalo Business First, CPA Software News, CPA
Journal, Journal of Accountancy, Rochester Business
Journal, Small Business Controller and other
business and professional publications. He wrote the
book Guide to Customizing Accounting Software, and
portions of numerous other books on implementing
computer technology. He can be reached on the
Internet at [email protected].
Why was Btrieve so important for
accounting?
LANGUAGE INDEPENDENCE
Btrieve did not care what programming language you
used to speak to it. That meant that ASVs could use their legacy
COBOL or BASIC code with Btrieve, while considering newer
technologies. This provided an upgrade path to both the
developers and the end users while new programming languages
were being phased in.
SPEED
As the flexibility of the accounting packages increased,
the reviewing magazines changed their reviews to reward speed.
Since an Editors Choice award could mean millions of
dollars in additional sales, Btrieve brought an instant advantage
over the non-Btrieve competition.
Speed is an important issue to the large companies
considering microcomputer-based accounting software as part of
their right-sizing or down-sizing activities. Mainframes and
mini-computers have their place in high-transaction volume
businesses; Btrieve on a micro dared to compete.
INTEGRITY
Users of COBOL, BASIC and MDBS systems on
microcomputers are accustomed to corrupted files and lost data.
Btrieve has the reputation being bullet-proof. As missioncritical jobs, computer applications on which the company
depends for basic business operations, moved to
microcomputers, a high level of integrity and reduced risk of
data corruption was necessary. Btrieve met this requirement,
along with standard tools to recover data.
NOVELLS SEAL OF APPROVAL
In the early 80s, the single-user, single-tasking MSDOS operating system environment was a frustration. Many
companies tried to offer ways around this limitation, with multiuser DOS extensions and local area network solutions.
However, few businesses were comfortable with any method of
having multiple DOS users share a common database.
The failure of OS/2 in 1987 to meet the multi-user
expectations of users may have been the catalyst that propelled
Novells NetWare into the limelight. Novells networks, once
known as notworks, emerged as the most popular way to get
multiple users into an accounting database for those who wanted
to use DOS applications and stay away from Unix/Xenix.
Novells purchase of Btrieve that same year made choosing
Btrieve as a database manager the logical choice for anyone
wanting to make sure their accounting software would be
compatible with Novell for years to come.
THIRD PARTY SOFTWARE AND TOOLS TO ADD
CAPABILITIES
Partnerships can make each partner stronger. ASVs
saw the opportunity to use partnerships to make their own
business situation stronger. If the ASV did not have to develop
their own contact management package, depreciation module or
report writer, they could concentrate on their basic product. In
addition, they could capitalize on the popularity of a third party
22
product as being compatible with their own.
Clever developers can add capabilities to others
software - if it is in a standard database file structure, like
Btrieve. One example, an executive information system (EIS)
called Forest & Trees (Trinzic Corporation of Waltham, MA,
800-952-8779 or 617-891-6500) provides a visual dashboard to a
business's operations. Borland International Inc.s defunct
ObjectVision was another powerful tool for augmenting the
accounting software packages capabilities.
CONSULTANT AND END-USER PRESSURE
When are you going to have a Btrieve version?
Finally, ASVs moved to Btrieve because consultants and endusers were demanding it. As third party Btrieve tools like report
writers became more sophisticated, users had to invest more in
mastering the technology. For consultants supporting multiple
accounting packages, having them all on Btrieve meant a greater
return on software and training investments.
BUT - WHAT OF THE FUTURE?
In the DOS world, where there is limited interapplication communications (IAC), a standardized database was
vital to provide common links between products. How about in
the Windows world - the land of Dynamic Data Exchange
(DDE) (or was that Dwight David Eisenhower?) and Open
Database Connectivity (ODBC)? Btrieve provides speed
underneath the Windows veneer that current IAC cant match.
How about referential integrity in the database, password
security and database dictionaries? Where Btrieve works fine for
smaller and growing companies, big companies are concerned
about software passwords being bypassed by data access tools.
Using products like Microsoft Access to get at accounting data
using Btrieve opens the door to anyone to see what the boss
makes. Access also limits the number of fields you can access in
a file. The youthful BTI has the tall task of making Scalable
SQL compete with the Sybases and Oracles of the world with
their mature development tools. Possibly it will be the support
of the ASVs that will propel BTI into greater dominance.
Accounting software vendors need an open architecture
to make sure future technologies dont pass them by. What are
the trends we are seeing in accounting software development?
ACCOUNTING SOFTWARE TRENDS
Windows
The race is on to sell Windows-based accounting. Only
a few vendors have had any success in putting even a limited
subset of their DOS functionality on the Windows market.
As with all development, ASVs are feeling the push for
graphical user interface (GUI, largely under Microsoft
Windows) development. Windows brings a characteristic loss of
speed to most accounting applications. However, the belief that
Windows-based accounting should be easier to use than DOS
(by definition) has propelled GUI accountings popularity.
Developing around Windows means a proper multiple
document interface (MDI), so that multiple accounting screens
can be viewed simultaneously. An order entry person can field
phone calls while switching to another window for cash entry in
free moments. Windows also brings font and printer control and
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
a more standardized menu structure for finding your way
around.
One of the biggest areas in Windows development,
however, is the screen customization and programming-like
functionality built into the new breed. The next generation
packages are bringing screen modification tools not unlike
Visual Basic or Microsoft Access: fields can be moved, hidden,
renamed, defaulted, and code can be added behind forms and
fields to add functionality. This ability to augment the software
is highly publicized, opening doors for developers to create new
functions for the software that does not interfere with the
programming source code.
Large Company Features
Just as the Honda Civic of the 90s is the size of the
Honda Accord of the 80s, so accounting softwares features are
migrating upward. The high end packages are trying to become
the foundation for international companies downsizing effort.
This has been met by vastly increased field sizes and efforts to
incorporate new technologies.
Increased field sizes are one of the most important
items for working with large companies. Chart of accounts,
purchase orders and invoice numbers are unusually (and
unnecessarily) long in larger businesses. In addition, conversion
of dollars to Lira or rubles can choke most systems.
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
Other international features by definition mean
expanded foreign currency capabilities, foreign language options
(like Kanji or cyrillic), and tax and business reporting needs for
other countries (like VAT).
Emerging technologies
Accounting software can no longer stand on its own.
Demands by large companies on other large companies and on
small companies has meant that most businesses are being
confronted with todays technologies of the future.
Bar coding printing and data input makes data
collection tasks like taking a physical count of inventories far
more efficient. In addition, some large companies will only do
business with companies that bar code their shipments and
documents.
Electronic Data Interchange (EDI) is the application
to application exchange of business transactions using public
standards for information content (EDI World, June 1994) - or,
in other words, a set of standards, with names like ANSI X12
and EDIFACT, for the way information is formatted and
communicated by computer between businesses. These
packets of information include purchase orders and
acknowledgements, inventory inquiries, invoices, and
notification that cash is being transferred to pay a bill. In tones
reminiscent of CB radio, youll now hear Accounts Payable
clerks asking, Wheres your 820 (EDI payment advice), good
buddy?
EDI spans barriers, like time zones, language
differences, or personnel cutbacks in data entry staff, hindering
communication between business partners. It also automates
business tasks, like inventory look-ups. With EDI your
customers can send electronic request to review your stock
availability without tying up your personnels time or making
you face the technical and security problems of giving customers
direct access to your computer system.
Computer mailboxes on third party communications
services like IBM, GE, AT&T and Control Data provide 24
hour a day dial-up capabilities for one step drop-off and pickup of the packets. These VANS (Value Added Networks) act as
intermediaries and can provide many additional helpful services.
Using these mailboxes, for example, companies in Japan, Africa
and India can leave purchase orders for a vendor in Colorado
during their respective business hours, which the Colorado
company retrieves when they open the next day.
As with bar coding, many large retailers like Wal-Mart
and K-Mart will only do business with companies that can
receive orders and acknowledge those receipts via EDI.
Document image processing systems use the computer
as an electronic filing cabinet. Hooked in with accounting, users
can view supporting documentation (scanned into the computer)
when reviewing the results of operations.
Lotus Notes integration (and other electronic mail
enabling) gets information to the people who need it
electronically.
These necessary hooks into accounting software make it
a ripe marketplace for developers to provide instant solutions,
while the ASVs determine their own future direction.
ACCOUNTING IMPORTANT FOR BTRIEVE
DEVELOPERS
Although accounting software is no longer the primary
driver for computer installations, it is still a main driver. Your
clients are probably asking for advice on which package to buy
and how to best customize their software to meet their needs.
You need to keep your house in order, too. Following is a brief
review of accounting softwares major pieces.
ACCOUNTING SOFTWARE MODULES
AND WHERE THEY FIT IN
Accounting software is general sold by modules, which
are associated with a business department or set of tasks.
Although each vendor offers a different set of products, it is
important to know the most popular modules and their role in
business.
The Big Three in accounting are the General Ledger
(GL), Accounts Receivable (AR) and Accounts Payable (AP)
modules. These are the most popular modules and found in most
businesses and departments. Most larger businesses track their
accounting on the accrual basis. That means that sales are
entered when they happen and expenses when they are owed.
Smaller businesses and service-based businesses often do their
accounting on the cash basis. In cash-basis accounting, sales and
expenses are recorded when cash is transferred, not when it is
owed. Although accountants generally agree that accrual basis
accounting is better for managerial oversight, it is important that
the system can track your business results in the way you need
to report it for tax and reporting purposes.
General Ledger
The General Ledger (GL) is the place where all of the
financial information of the company gets summarized.
Information from all of the other modules flows to the General
Ledger to be analyzed, summarized, and presented in financial
statements. Budgets and prior year information is maintained in
the GL so management can compare the results of operations
with prior years and with forecasted results.
Most GL packages will let you automatically bring over
accounting information from other modules without retyping.
Some will also let you bring in summary information from other
systems in a ASCII, Lotus worksheet or dBase III format.
Development opportunities: interfaces from custom
developed packages; automatic links out to spreadsheets.
Accounts Receivable and Cash Management
The Accounts Receivable (AR) module is the
storehouse for customer related information. Depending on your
industry, your customers may be known by other terms, such as
clients or patients. The basic information about your customers
(like addresses and primary contact names)and salespeople are
kept here. Cash receipts, finance charges, monthly statements
24
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
and aging reports are processed here. For smaller installations,
some basic invoicing capability in the AR module may be
helpful.
AR works closely in conjunction with Order Entry and
Billing systems.
Cash Management tools may be as simple as cash
expectation reports to full credit monitoring systems.
Development opportunities: visual dashboards of cash
position, links from custom order entry systems, integration
with EDI systems for cash received.
Accounts Payable and Bank Book.
The Accounts Payable (AP) module automates the
check writing process. The AP system can print checks for you
or track checks you have written by hand, as well as recording
bank charges and electronic transfers.
Accounts Payable works closely in conjunction with
Purchase Order systems.
Bank book systems help with check reconciliation and
maintaining bank balances.
Development opportunities: Integration with ASCII
files from banks for check reconciliation; links from AP to AR
for agents, billbacks of expenses.
Payroll and Human Resources
The fourth entry in the Big Three is payroll (PR).
Although most accountants recommend that smaller businesses
use outside firms to process payroll, due to the ever changing
payroll tax laws and rules, internally prepared payroll is helpful
for job oriented businesses. Payroll systems collect employees
time, print payroll checks or direct deposit stubs, and prepare
reports for taxing jurisdictions, government requirements and
management purposes.
Human Resource (HR) systems track additional
information, such as the results of reviews and raise histories, as
well as skills and training.
Payroll systems feed information to job cost systems
for analysis of the actual costs of a job, including labor,
materials and overhead.
Development opportunities: integration of timeclock
systems; Union and other special reporting.
Inventory Management
For businesses that resell or manufacture, keeping track
of the costs and usage of inventory is important. Inventory
Management (IM) systems track the quantities on site, the
current demands for each item from internal and external
sources, and expected replenishments. They also assist in doing
physical counts.
Each industry has special tracking needs. Retail
environments may need to have multiple item numbers (UPC,
internal, manufacturers) for the same item. Manufacturers need
to track the identifiers of engineering drawings and instructions
for manufacturing (routings and bills of material) for each item.
Users need to be able to quickly discern the investment in their
inventory, as well as the availability of items for use or sale.
Development opportunities: work in process systems;
receiving and purchasing systems.
Order Entry
Presumably every business is in existence to make
money. Tracking the requests for product or services and the
fulfillment of those requests goes by different names for each
industry. Retail businesses have point of sale, where most
See Accounting on page 36...
Programming for Hire
By Jon Burke, Business Logic
The computer industry hasnt turned out at all as I
expected. Since the early 1980s when personal computers
where just making their debut, I expected the computer industry
to go the way of the automotive field. With automobiles, the
small, creative independent manufacturers were pretty much on
their way out by the late 1940s. By the 1960s the independents
were completely gone, and only the giant mega-corporations
remained. Thats how I expected the computer industry to fare.
But I was wrong. Instead of the large scale calcification
I expected, the giants in the computer industry rose up, were
struck down, and left in their wake a
A large part of conglomeration of small, hungry,
innovative firms that are vying
successfully for overall
the industry has
control of the industry.
gone to small shops and Certainly, IBM, DEC,
and Hewlett Packard
are still around.
independent consultants.
However, a quick
These gunslingers are grab- look through any
trade paper will
show hundreds and
bing a larger and larger
thousands of small
companies some still working
piece of the pie.
nearly out of back yards hassling
the major players in the field, and often winning. And this trend
seems to me to be on the upswing.
Software application development is following the same
trend. Large companies such as Platinum have recently had their
difficulties, and many arent doing very well at all. A large part
of the industry has gone to small shops and independent
consultants. These gunslingers are grabbing a larger and larger
piece of the pie, and this has given rise to an unusual problem.
In spite of the fact that small companies have been a part of the
American business scene since before George Washington, it
seems that not many people know much about how these
companies operate. Everyone knows how to buy a car from
General Motors, but how many would know what to do if they
wanted a Tucker instead? The same applies if youre the one
making the car how do you get started and stay started?
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
Consider these questions taken from a letter I recently
received: How much should I pay a programmer to write
code? How should I handle any bugs I might find, in terms of a
contract? What other items should a contract contain? Where do
you find a good programmer and how do you tell? What about
confidentiality and nondisclosure?
These are very good questions not just for the
potential consultant or programmer but also for the party who
hires the contractor.
Before I start trying to answer these questions, Id like
to lay some ground work and discuss the overall matter at hand.
To my mind, the central issue in contractor-to-contractee
relations is trust. The contractor runs a risk in undertaking a
contract. Will he get the estimates right, or will he wind up
working for next to nothing? Will his client pay on time or at
all? How does the contractor protect himself?
For the client, the questions are just as tough, if not
tougher. Typically, the client is hiring knowledge and
experience over and above what they have available to
themselves. This means that whoever they hire will be
performing magic something they will find difficult or
impossible to evaluate during the development cycle. So they
have to rely on trust, and trust doesnt come easily. Will the
contractor get the job done at all, and if so, will it be on time?
And the Big Question: How Much Will It Cost?
While these questions remain unanswered, tensions
inevitably rise, and the job at hand gets a lower and lower
percentage chance of successful completion. Its been my
experience that, if the client and the contractor are both
seriously afraid about how the job will come out, trouble is on
the way. The converse is likewise true: If everybody concerned
is convinced of each others ability and good will,
insurmountable problems seem to fade away and the likelihood
of the project reaching a successful conclusion approaches
certainty.
So, I believe its absolutely fundamental to create and
maintain trust throughout the life of a project. A lot of my
answers to other questions revolve around this way of thinking.
Keep this approach in mind and a lot of the other questions start
to answer themselves.
How much should I pay a programmer to
write code?
On the surface, this looks to be a simple question, and I
guess I could just brush it off with a quick dissertation on
programming rates. However, the real meat of this question
isnt so much the rate one pays or receives for programming
services, but rather how the overall project gets paid off, what it
costs in the long run, and how payment is tendered. To my
mind, this is a much more important question. Ill answer both.
Programming rates vary considerably based on a
variety of indices. Geographic location, the programming
language in question, the type of task to be programmed, all
play a part. Typical programming pay (money received by the
contract programmer) in Southern California runs from maybe
$22.00 per hour on the low end to perhaps $150.00 per hour on
the higher end, with the majority getting between $32.00 to
about $65.00 per hour. Usually, the programmers receiving the
lower pay rates are acting as subcontractors, so its rare that the
client will pay rates in the twenty to thirty dollars an hour range. payment, the client got more and more uncomfortable. Huge
sums of money were piling up, and there was no commitment
You can expect client rates to be between 20% and 40% higher
than what the subcontractor programmer receives. Keep in mind on the programmers side, other than his professionalism, that
the project would actually reach completion. The project finally
that these figures are pretty rough.
There are other factors that come into the equation besides finished, about 15% over budget (a not unusually high overage
in this kind of project), but the client
raw cash. Flexible hours, work that can be
was a nervous wreck, and the
performed off-site, location of the site,
relationship had deteriorated
and the type of work all figure into it. If the
ΤΟ ∆Ο ΛΙΣΤ
substantially. I dont recall the
work can be performed away from the
ι. δατα κοµπρεσσιον αλγορυθµ
programmer getting any more work
client site, or if the hours during which the
ιι. ρεΦορµατ ′αρδ δισκ
ιιι. ∆ΕΒΥΓ ΠΡΟΓΡΑΜ
from that client, and the software
programmer must work are not cast in
σωκ θε βυµς φορ α λοτ οφ
created during that project deteriorated
stone, this can count for a large reduction
δραχµα
βοι αρε θη γοννα ω µε
from neglect. Within one year, the
in rate of pay. Alternately, if the work
φορ θις
client company removed the software.
must be done between the hours of 9:00
Everyone lost. The alternative,
and 5:00 every week day at a factory
however, is justifiably scary for the
location, the client can expect to pay
contractor. How can you say what will
premium prices.
happen in three months? Six months? A
Long term contracts typically
year? In my experience, the vast
pay/cost less per hour than short term
majority of project estimates turn out to
jobs. In this case, the programmer trades
be wildly wrong, and almost all of
some income for security and a larger
them are optimistically so.
overall payoff, and its usually a good
The only way around this is designing
trade for all concerned. I typically discount
the project in great detail before
projects that take three months or more by
bidding it. Typically, Ill design the
as much as 25%, all other factors being
database and lay out all the DDFs. Ill
equal.
complete screen layouts and report
Youll notice that until now, Ive
samples. Ill write up the proposed flow
discussed hourly rates exclusively. I do
Project estimation is nearly a
of operations in clear, nontechnical
this because I dont think you can estimate
black art in the programming
terms. I include a total project bid, a
or track a project in any other way you
business
list of milestones, and a payment
have to consider the hours involved and
price accordingly. However, hourly pay is not my favorite method schedule. This later says what completed work the client will be
of remuneration although its certainly the most prevalent in the shown in exchange for a check of a designated amount. I try to
industry. The reason it is the most common payment method is that time it so a milestone and its accompanying check show up
fixed bid projects must be effectively estimated. And project about every week or two. You should seriously avoid letting
milestones spread out over more than 30 days under any
estimation is nearly a black art in the programming business.
circumstances.
Folks who contract to build houses or lay asphalt,
In preparing one of these specifications, I think its
armed to the teeth with experience and automated estimation
programs, complain mightily about how tough project estimation wise to err on the side of extra detail. This sounds like a huge
amount of work, and it is. However, until you do this, there is
is, and how inadequate their resources are. Theyre right its
absolutely no way you can effectively estimate what a job will
tough but it may be twenty times tougher for the contract
cost.
programmer. At least, a company laying an asphalt road has
While I may not know what it will cost to complete the
laid many roads before. It may go up or down, the bedding may
be soft or hard, the climate may be cold or hot, but a road, after entire project, I can generally guess pretty closely how long this
estimation phase will take. So I tell my client the truth: I cant
all else, is still a road. Programmers, on the other hand, are
estimate the project cost until the specification phase is
typically asked to perform tasks in completely unrelated fields.
complete. It will take me x number of days/weeks/months to
Looking over our books, I see my company handled over the
complete the estimate, and it will cost this amount. The amount
course of one year a program to evaluate the density of biota in
varies depending on the project. Usually, charges run between
an estuary, a shop floor control program that interfaced with
$1,500 and $15,000 for a specification. Typical terms are 25%
robotics equipment, a project to track cost of production on
to 50% to start and the rest on submission of the specification.
wood products, and the rescue of a database that a client had
You should anticipate changes in your first draft of
accidentally encrypted. And thats in addition to ongoing work.
specification, mostly due to misunderstandings, missing a small
All of these required different skill sets.
but important point, etc. These, I correct for no extra charge.
These are all good reasons why fixed bid work isnt in
For major changes in the concept of the project, you should bill
vogue today. However, I think the reasons in favor of fixed bid
projects outweigh the dangers. It all comes back to trust. Hourly extra.
A whole primer on project estimation is beyond the
billing tends to be a lot more protective of the contractor, and it
scope of this article. However, Ill mention a few of the
tends to put the client at a higher level of risk. I recall a project
concepts that represent the toughest hurdles I generally
that progressed on schedule, with milestones being met and the
encounter when estimating a project, in hopes that theyll help
programmer getting paid every two weeks. But with each
27
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
even a little.
Nothing happens that takes less than four hours
In larger projects, this can go up to a day. If you think
that a simple report, for example, can be completed in one hour,
more power to you. However, you should remember that a
single mistake means getting the error report, fixing it,
recompiling (or the equivalent), sending the fixed version to the
client, and getting the report that says the error is fixed. I can
barely write that sentence in under one hour. In a fixed bid
situation, its wise to build in some time for error control.
Add a percentage to the overall project cost to cover
mistakes. Tell your client about this too.
In a fixed bid situation, its difficult to go back for
more money once the project is underway. You absolutely have
to build in a buffer for when (not if) mistakes happen. From the
clients point of view this is equally wise major accidents can
easily wipe out a project budget. Keep a safety buffer.
Work from previous projects.
Its a good idea to go back and reestimate previous
projects, especially those that werent fixed bid. It gives you an
idea of what reality is like and is sharpens your skills
considerably.
When a project estimate is high, consider that it might
also be accurate.
This works with the last suggestion. A typical mistake I
still make is to look at a project estimate and get blown away by
the huge numbers I come up with. Okay, sometimes theyre
wrong. Other times, however, they turn out to be uncomfortably
close to reality. Look at some past projects that werent fixed
bid. How much money and time really got spent in the long run?
Youll note that a lot of this talk about planning can apply to
hourly work as well as fixed bid projects. However, once Ive
submitted a specification that states how long certain phases of a
project will take, I find that Ive inadvertently crossed over into
the land of fixed bids without noticing. So it becomes the same
thing after all.
How should I handle any bugs I might
find, in terms of a contract?
The client has a reasonable right to assume (and insure)
that their shiny new software works once its installed.
Likewise, its also reasonable and fair for the programmer to
consider the project complete after a certain point, and not to be
haunted by a project like Marleys ghost. The best way Ive
found to handle this is to issue a warranty that fixes any bugs
that occur over a specified period of time, usually thirty to
ninety days, for no extra charge. Bugs discovered after that time
period are billable.
This may sound a bit harsh, but its not really not if
its done right. I tell my clients the following: The system
28
WILL have bugs. Everyone must expect them and plan for
them. Ive never seen a large custom system written entirely
bug free, and I doubt that such a thing is possible. Bugs are,
unfortunately, part of system development. Test everything I
install as much as possible during the warranty period. If you
dont test then, finding a bug after the warranty is almost a
certainty. Bugs must be repeatable. If I cant see the bug and
make the bug happen, I cant fix it. However, when nonrepeatable bugs occur during the warranty period, I log them.
Later, if I find their cause, I almost never charge to fix them.
Dont commit valuable, unprotected data to a system until
youre certain the system is stable.
The real reason I put a time limit on this (and I tell my
clients this too) is that I want to fix all of the errors while its
still fresh in my mind. I cant think of anything more
disconcerting than having to fix a bug on a project I worked on
five years ago in code the client is just now getting around to
testing. So Im not too inflexible about the exact timing on error
reporting. If the client finds a bug on the ninety-first day, Ill
consider it warranted, as long as the testing effort is underway.
What other items should a contract
contain?
First, I should say that I favor agreements versus
formal contracts, even on larger jobs. Agreements can be just as
binding as formal contracts if theyre done right, and they seem
to set a friendlier tone. I suppose that, if I took on a job with a
client I didnt trust, I might go with a formal contract, but I
cant see myself taking on such a project in the first place.
In either case, contract or agreement, Ill skip over the
boilerplate that all these seem to contain youre better off
getting that from a lawyer or at least a preprinted form prepared
by lawyers, than you are from me. Instead, Ill simply mention
the points I think are most important:
Include specific references to the specification as the
project definition. The specification defines the scope of work
and the project. If the spec doesnt say it, it wont get done.
Dont try to describe the project in the agreement it just
doesnt work. A specific reference to the Payment Schedule
should be part of your specification. Payment terms. Mine are
due upon presentation of invoice. I try to include these in the
agreement. Total payment amount. Likewise, I include this too.
I tend to avoid penalty clauses I think they make for bad
feelings. I dont charge penalties for late payments, as thats
almost never been a problem for me. I wont accept a contract
that includes a performance penalty or late penalty that effects
me adversely. Either way, this gives the parties concerned a
reason to find fault in each other. Thats not a healthy
relationship. Confidentiality. I note in any agreement that all I
have written is proprietary and confidential, and that release of
this information will cost me sums far in excess of the project
cost. Thats the truth too how long does it take to develop a
file access routine that you use in all your work but dont bill
for directly? I require that my client treat my information as
proprietary and confidential, and that they take measures to
insure that it stays this way. Source Code. I specify who gets the
source code at the end of the project. Personally, I prefer that
the clients have it they seem to feel more comfortable when
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
they dont feel trapped into using me and me alone.
Theres much more that is typically included in such
documents, but these are my favorite topics. Anyone seeking
more information should contact a legal professional.
Where do you find a good programmer,
and how do you tell?
This question addresses a rather subtle problem: How
to you test for expertise in a field where you have little or no
expertise yourself? While I dont know of a scientific answer to
this, there are a few things you can do. Get References and
call them. While any contractor in their right mind will only
give references that speak well of them, you can still get lots of
information about a contractor from anyone they have done
business with before. Check source code. I often ask
programmers to bring me a sample of source code theyve
written that they are happy with. Even if you dont program,
you can tell a lot from this. Are there lots and lots of
comments? Is the code neat looking? I know this last may sound
silly, but try to lay out a large case statement without the proper
indentations and see if you can understand it yourself! Ask the
programmer to explain why they are happy with this code. If the
programmer can explain clearly without reverting to
technospeak, thats a real plus. Find out if you share any mutual
contacts and call them. Programming is a small world its
not unusual for me to find out that a prospective contractor
knows some of the same people I do. If thats the case, I call
them up and ask their opinions.
loss. When the plaintiff made your confidential documents
available to others, what damage did you incur? The fact that
damage will result if your work is revealed should therefore be
included in the agreement.
Another important thing to remember is that you cant
restrict a person from doing his or her job. I recall my lawyer
showing me an agreement that tried to exclude a programmer
from working as a programmer after he left the firm, based on
the idea that all the techniques he learned were proprietary.
Needless to say, this didnt stand up. When writing a
nondisclosure agreement, I try to make sure that what I restrict
is very specific and does not effect the contractees overall work
picture.
One last thought on the matter: Nolo Press of Berkeley,
California produces a book called Software Development a
legal guide. Its written by attorney Stephen Fishman, and its
really excellent. More important, it also contains sample
contracts, agreements, and nondisclosure contracts. Unless your
lawyer is s specialist in intellectual properties and the data
processing industry, this book may well tell you more than your
own lawyer can. The cost is offset by the sample contracts
alone.²
Jon Burke is an independent programmer, consultant, and
occasional free-lance industry journalist. Jon is president of
Business Logic, 5 Vista Del Ponto, San Clemente, CA
92672. He may be reached at: (714) 492-0442 CompuServe:
75470,3115 Internet: [email protected]
What about confidentiality and
nondisclosure?
Again, Im not a lawyer and this is an especially tricky
aspect of law. However, Ill be glad to pass on what Ive
gleaned over the years. Youre advised to seek further council
from professionals before acting on anything I say here.
Excluding the cases where national security is an issue,
violation of confidentiality and nondisclosure agreements are
both served in civil court no criminal penalties, at least as far
as Ive ever heard. If youre trying to non-disclose a single
programmer and they dont have the financial wherewithal to
make a law suit viable, and unless you can prove they actually
profited directly from a disclosure of protected information,
there isnt too much you can do. The biggest damage one
typically incurs from violating nondisclosure agreements is that
he or she doesnt get to see any more secrets and, as this
industry is a close knit one, others hear of the violation and
react with distrust.
If, on the other hand, youre concerned about
confidentiality as it pertains to another firm, there is a lot you
can do, starting with the typical nondisclosure agreement. These
are often boilerplate, and you can get preprinted versions. Also,
take a look at any of the larger companys agreements that come
out with beta tests, some product pre-announcements, etc. If you
have access to one of these, taking an example from them can
help. (Note: copying them may not be legal.)
Like any other civil matter, judgment will depend upon
(800) 828-7438 or (615) 386-3100 FAX: (615) 386-3135
transactions are fulfilled immediately. Wholesalers have order
entry or customer order processing, where documents called
picking tickets are prepared after the order is entered, and the
order is billed after it is determined what can be shipped.
Professionals use time and billing systems, and those in
construction, job costing. Those in the computer industry need
quoting, service dispatch and time and billing. These modules
will be covered in more detail in the next issue.
Development opportunities: Electronic data interchange
integration; special query tools to help customer service quickly
find open and closed orders.
Small tweaks of the software to make operations more
efficient can be done easily in the Windows environment. The
ASVs let you add functions to menus to run your program from
within the main software.
Many ASVs are marketing their own programming
development environments for their packages. Whether it is
Dexterity for Great Plains Dynamics or upcoming tools from
Libra for their new Windows software, end users will be finding
that development is not as easy as they think. Mastery in one of
these environments may be a key to future business.
Purchase Orders
A number of developers have written applications to
meet special needs that work in conjunction with off-the-shelf
accounting. This means they do not have to take on as much
responsibility, and can co-market their products with the ASVs.
When it is time to replenish inventory, buy goods
needed on jobs, or request outside services, companies user
Purchase Order (PO) systems to track the companys
commitments. PO systems are used for printing and tracking
open orders, keeping files on available and historic pricing, and
entering receipts (and possibly the payable due upon receipt).
Development opportunities: EDI integration; receiving
systems; custom databases of pricing and history.
THE OPPORTUNITIES
Accounting Software is a lucrative environment for the
developer. Very few companies are 100% satisfied with the
feature sets of off-the-shelf software. In fact, if you polled the
potential users of accounting software for their wants and needs
list, you would rarely find a package that met more than 8085% of their needs. The developer can help in three ways.
Modifications
30
Vertical applications
User query tools
Todays accounting collects and keeps a great deal of
information -just getting at it is a problem. The reports and
inquiry screens of most accounting software are often criticized
as containing too much. Developers can prepare tools for letting
people get at their selected information more easily.
Conclusion
Every major vendor of off-the-shelf high-end
accounting software has moved to Btrieve as the basis for their
next generation software. This is an exceptional time for the
Btrieve developer to take a look at the marketplace, for their
clients and their own sakes. ²
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-
Letters and Comments
Please let us hear from you! We want to make Btrieve
Developers Journal just right for you. Send us any news,
information, comments, suggestions, or anything else to
BDJ, 2416 Hillsboro Road, Suite 201, Nashville, TN 37212
Dear Btrieve Developers Journal,
I have quite a few magazine subscriptions, but I can’t find the time to read any of them. I think yours may be the only one that I can
get to on a semi-regular basis and I just have to read it from cover to cover. Of course, if I can free up that time, maybe I could have
time to read the Table of Contents of my other magazines - just to see what I’m missing. Keep up the good work! Also, there seem to
be quite a few people clamoring for ODBC improvements. I assume youre keeping an eye open for the latest status on these
projects.
Davin Church, Mesquite, TX
Davin,
Thanks for the kind words... We have been inundated recently with mail on ODBC. Ron Harris, President and CEO of BTI assures us
that BTI is formulating a comprehensive ODBC strategy so that this problem will be solved. Here are some other comments that we
have received recently:
The Intersolv ODBC driver is difficult to install, has quirks in usage, and is not even implemented correctly. For example, they
maintain cursor support by issuing a WHERE statement containing the name and value of EVERY field in a table. If you have large
records, the buffer overflows and you cannot access your data. BTI has great internal cursor support in Scalable SQL. Someone
needs to implement a proper ODBC driver that takes full advantage of that product.
Lance Prager, CIS: 71154,1341
I would very much like to use Btrieve with an ODBC driver (using PowerSoft products) but the royalties are ridiculous. Intersolv/
Q+E wants somewhere around $60 per site and I need about 2,000 sites. BTI needs to write their own ODBC drivers. If anyone else is
having any similar problems or worries, please let BTI know. Enough people could get the ball rolling. Michael Binette, Stoneham, MA
We’ve been using both the Q+E and Microsoft ODBC drivers for Btrieve from within PowerBuilder for months... and we hate it. Both
drivers have their problems, so a ‘true’ ODBC implementation from BTI would make us very, very happy. If beta testers are needed,
we would be more than happy to volunteer.
Rob Rene, Provo, UT
As you know, I am working on a book about Btrieve for Addison-Wessley Publishers. Now that things are progressing, I have
decided to look in to including a chapter on third-party tools that work with Btrieve and Scalable SQL, both commercial ones (like
your DDF Builder for Windows and Smithware Controls for Btrieve) and shareware (such as Doug Reilly’s BTFiler). I would
appreciate your passing this information along to any vendors who may wish to be included in this section. I’ll keep you posted on
how things proceed.
Jim Kyle, Oklahoma City, OK
I just received my free copy of Btrieve Developer’s Journal today... and was it worth the wait. You guys sure did a good job on your
magazine. Lots of good technical stuff. After reading the center section contributed by BTI, I now have a much better understanding
of what Scalable SQL is about. I also liked the article on “Unlimited File Sizes” via a virtual filing system. I am sending in my
subscription form tomorrow morning. Since we also purchased your Smithware Controls for Btrieve a few days ago, we are now
searching the delivery people coming into and out of our building. It’s been at least two days now since we ordered them and we can’t
wait!
John Dunbar, Houston, TX
Would you be interested in distributing the content of Btrieve Developer’s Journal electronically to your audience through Btrieve’s
on-line service?
Keven Pietzsch, Columbus, OH
Kevin,
We are working with Chris Ojeda, BTI’s CompuServe SYSOP to set this up. Look for an electronic edition of all back issues of BDJ by
the end of the year.
It’s good to see some third party companies like Smithware tackling the information void in this industry. Product is only a small part
of what developers want from a company. We want data, data, and more data. Keep up the good work.
Robert Lauer, Newton, PA
31
(800) 828-7438 or (615) 386-3100
FAX: (615) 386-