Ask me later about…

Transcription

Ask me later about…

How to Upgrade Your Application
with no Downtime
(and no Additional Costs!)
Oren Nakdimon
www.db-oriented.com
 [email protected]
 +972-54-4393763
@DBoriented
First of all, let’s gather
some statistics…
© Oren Nakdimon
This presentation is available in http://db-oriented.com/presentations
A QUICK SURVEY (1/4)
Do you know what Edition
Based Redefinition is?
© Oren Nakdimon
Have you ever used
Edition Based
Redefinition in
production?
© Oren Nakdimon
Which Oracle versions do
you use (or plan to use) in
production?
12c
11g R2
11g R1 or earlier
© Oren Nakdimon
Which Oracle editions do
you use (or plan to use) in
production?
Standard Edition
Enterprise Edition
© Oren Nakdimon
WHO AM I?
A CHRONOLOGY BY “ORACLE YEARS”
Where:
IAF
When:
Oracle 6/7 [1991-1997]
Where:
Golden Screens
What:
Developer
When:
Oracle 8 [1997-1998]
What:
Server Group Manager
Where:
TELEknowledge
When:
Oracle 8i/9i [1998-2003]
What:
DBA Group Manager
Where:
Olista
When:
Oracle 10g/11g [2004-2011]
What:
VP R&D + Israel Site Manager
Where:
Where:
When: Oracle 11g/12c [2011-]
When: 2015-
What:
What:
Freelance Consultant
Database Expert
© Oren Nakdimon
@DBORIENTED
© Oren Nakdimon
HTTP://DB-ORIENTED.COM
© Oren Nakdimon
SHARING EXPERIENCE FROM…
A
24x7 system
 Millions of end-users
 Thousands of concurrent end-users
 All around the world
 Lots of PL/SQL code
 Frequent upgrades
 Intensive use of EBR
© Oren Nakdimon
THE BOTTOM LINE
I
think EBR is great!
 It is quite a big and complex feature, but…
 It is very easy to start using it
 It may take some time to know all the details
and nuances
 Warning: as with any other feature, make sure
to test it thoroughly before you decide to apply
it in production
 Issues that are out of the
presentation’s scope
© Oren Nakdimon
AGENDA
 Application


upgrades
Scenarios
Methods
 EBR
introduction
 Upgrade use cases




Requirements
Challenges with online upgrade
Solving with EBR
Tips
© Oren Nakdimon
APPLICATION UPGRADES
Scenarios
Application X
Application X
+ some change(s)
© Oren Nakdimon
© Oren Nakdimon
 Upgrades
are inherent to every application
lifecycle
 They may be:





Small or big
Frequent or rare
Simple or complex
With or without schema changes
Introducing new functionality, changing existing
functionality, or removing functionality
© Oren Nakdimon
Methods
EDITION-BASED REDEFINITION
Introduction
EDITION BASED REDEFINITION
 EBR
is a feature set that lets you upgrade the
database component of an application while it is
in use, thereby minimizing or eliminating
downtime
 Introduced
 EBR
in 11gR2
is supported in all editions, and requires no
special license
© Oren Nakdimon
EDITION BASED REDEFINITION
 The
fundamental ability is that different copies
of the same object may coexist
 Not all objects are editionable
TOM
JERRY
Edition1
PKG_A
MY_VIEW
Edition2
PKG_A
MY_VIEW
TABLE_X
TABLE_Y
PKG_A
MY_OBJ
MY_OBJ
© Oren Nakdimon
EDITIONS
 Edition
is a non-schema object
 There
must be at least one edition in the
database

The initial edition is ORA$BASE
 There
is always one database-level default
edition
© Oren Nakdimon
EDITIONS – CONT.
 Every
new edition is created as a
child of an existing edition
(11.2, 12.1), each
edition may have at most one
child edition
Edition1
 Currently
Edition2
 Enabling editions to users
 Granting use on editions
Edition3b
Edition3
© Oren Nakdimon
UPGRADE USE CASES
APP_MGR
(package)
do_something
PEOPLE_DL
(package)
add | remove
PEOPLE
(table)
© Oren Nakdimon
APP_MGR
S
PEOPLE_DL
B
@people_setup
S
B
Table
© Oren Nakdimon
USE CASE 1 – THE REQUIREMENTS
A
package body should be changed
 No change in package spec
 No change in table structure
© Oren Nakdimon
USE CASE 1 – THE CHALLENGES
 Blocking


Compilation is blocked by active clients
Clients are blocked during compilation
© Oren Nakdimon
Tip
© Oren Nakdimon
SESSION EDITION
 Each
 The


 To
session uses one edition at a time
current session edition:
SHOW EDITION (SQL*Plus)
SYS_CONTEXT(‘userenv’,’session_edition_name’)
change the session edition:
ALTER SESSION SET EDITION = edition;

Must be the first statement of a transaction
© Oren Nakdimon
EDITIONED OBJECTS
 An
editioned object in an edition is either:
Inherited

p
or

edition1
Actual
 Note:
edition2
actualization is irreversible!
p
@end_user_session
@use_case_1
edition3
© Oren Nakdimon
APP_MGR
ora$base
V1
S
PEOPLE_DL
B
S
B
B
Table
© Oren Nakdimon
A
package spec should be changed
APP_MGR
ora$base
V1
S
PEOPLE_DL
B
S
B
B
Table
© Oren Nakdimon
 Invalidation


Compilation errors (hopefully not…)
Object dependency

Revalidation occurs automatically when an object is
referenced
 Multiple
interrelated objects need to be
changed
APP_MGR
S
PEOPLE_DL
B
S
B
Table
© Oren Nakdimon
USE CASE 2
A
APP_MGR
ora$base
S
PEOPLE_DL
B
S
B
B
V1
Table
V2
S
© Oren Nakdimon
USE CASE 2
A
APP_MGR
ora$base
S
PEOPLE_DL
B
S
B
B
V1
Table
V2
S
© Oren Nakdimon
A VERY IMPORTANT FOOTNOTE
 Source:
http://www.oracle.com/technetwork/database/features/availabilit
y/ebr-455513.html
© Oren Nakdimon
Tip
 How to identify dependent
objects
 Different ways to actualize
© Oren Nakdimon
A
new column should be added
 It represents a new logic
 An existing package should be changed
accordingly
© Oren Nakdimon
 Invalidation

Code dependent on the table is invalidated (!)
APP_MGR
ora$base
S
PEOPLE_DL
B
S
B
V1
V2
B
B
S
B
Table
© Oren Nakdimon
ELIMINATING INVALIDATION
Program
Unit
View
Table
© Oren Nakdimon
EDITIONING VIEWS
 Editioning
Views are:

Views (hence editionable)

Deliberately limited:
One per table
 May contain only the SELECT and FROM clauses
 The FROM clause refers to a single table
 The SELECT list may contain only columns and aliases (no
expressions)


DML triggers can be defined on them
© Oren Nakdimon
Editioning Views are
the Interface
between the
Application and the
Tables
© Oren Nakdimon
Tip
 Other schema changes that
cause invalidations
 And how to handle them
@use_case_3
© Oren Nakdimon
Tip
© Oren Nakdimon
A
 It replaces an existing column
 Cutover
@use_case_4
© Oren Nakdimon
 Keeping
the old representation and new
representation in sync until the cutover
© Oren Nakdimon
CROSSEDITION TRIGGERS
A
crossedition trigger is a “bridge” for moving
data between editions
 Temporary in nature
 Forward
crossedition triggers transform preupgrade representation to post-upgrade
representation
@fce_trigger
© Oren Nakdimon
Tip
 Mass update of the data
© Oren Nakdimon
Tip
© Oren Nakdimon
USE CASE 5
A
 It replaces an existing column
 Rollover
© Oren Nakdimon
REVERSE CROSSEDITION TRIGGERS
 Reverse
crossedition triggers transform postupgrade representation to pre-upgrade
representation
@rce_trigger
© Oren Nakdimon
Tip
© Oren Nakdimon
EXPOSING THE NEW VERSION
 Database-level:
ALTER DATABASE DEFAULT EDITION = edition;

Session level

Statement level – using
DBMS_SQL.PARSE

Service level
 ORA-04068
 After Logon trigger
© Oren Nakdimon






Retiring editions
Dropping editions
What’s new in 12c
Jobs and editions
DB links and editions
Whatever you like…
© Oren Nakdimon
THANK YOU
Oren Nakdimon
www.db-oriented.com
 [email protected]
 +972-54-4393763
@DBoriented

Ask me later about…

Transcription

Similar documents