Template Development FAQ

Transcription

Template Development FAQ
Cloud Mapping Designer (CMD) - FAQs
1. Where can find detailed information about the cloud mapping designer?
You can refer to the Informtica Cloud User Guide. You can refer to following chapters
 Mappings
 Mapping transformations
 Expression macros
 Mapping configuration
2. What are the transformations available in the Cloud mapping designer?
The transformations available in cloud mapping designer are
Transformation Description
Source
Reads data from a source.
Target
Writes data to a target.
Aggregator
An active transformation that performs aggregate calculations on groups
of data.
Expression
Filter
Joiner
A passive transformation that performs calculations on individual rows of
data.
An active transformation that filters data from the data flow.
An active transformation that joins data from two sources.
Lookup
Looks up data from a lookup object. Defines the lookup object and lookup
connection. Also defines the lookup condition and the return values.
A passive lookup transformation returns one row. An active lookup
transformation returns more than one row.
Mapplet
Inserts a mapplet into a mapping. A mapplet contains PowerCenter
transformation logic that you can create and use to transform data before
it is loaded into the target.
Can be active or passive based on the transformation logic in the mapplet.
Normalizer
Processes data with multiple-occurring fields and returns a row for each
instance of the
3. Is Debugger is available in CMD?
The debugger is not available in CMD. There are other ways to troubleshoot the mapping.
You can create a mapping configuration task and configure the following options
In the schedule option
a. Choose “Execution mode” as Verbose. Use this mode only for troubleshooting as this
will output lots of data into the log and slow down performance
b. Use “Error handling options” in the Advanced Session Properties
4. Does Cloud mapping designer support Dynamic lookup?
No, the cloud mapping designer does not support dynamic lookup.
5. Why don't I see field level links between transformations as in PowerCenter?
In a CMD, transformations can be connected using a link to specify the sequence of
transformations that need to be applied on the data flow.
In CMD, there is a single link from the upstream transformation to the subsequent
transformation. By default, the downstream transformation inherits all incoming fields from an
upstream transformation. But you can use field rule to exclude incoming fields. You can also
rename incoming fields to avoid name conflicts.
6. How to avoid the naming conflict when transformation (like joiner) end up with two fields with
the same name?
A name conflict occurs when fields that come from transformations that are connected to a
single joiner transformation has the same name. When you validate a mapping, the Mapping
Designer notifies you of any field name conflict. To resolve a field name conflict, you can rename
incoming fields in bulk. To avoid field name conflicts, you can create field rules to rename fields
from upstream transformations.
You can rename fields individually or in bulk. When you rename fields individually, you select
the fields you want to rename from a list of incoming fields. Then you specify the name for each
of the selected fields. When you rename in bulk, you can rename all fields by adding a prefix,
suffix, or pattern.
7. How to delete a transformation or a link?
Use the Delete icon on the mapping designer toolbar to delete the selected transformation or
link.
8. How can I validate a mapping?
Use the Validation icon on the mapping designer toolbar to open the validation panel to
perform mapping validation.
9. How to run a task using the mapping created using cloud mapping designer?
To run a task using the mapping create a mapping configuration task.
10. Can the source and target connections and objects be parameterized?
Yes, the source and target connections along with the objects can be parameterized.
11. Can I modify the parameters once created?
Parameter attributes like name, label, description cannot be modified. You have to delete and
recreate the parameter.
12. Can we create task flow for CMD mapping tasks?
You create a task flow to run multiple tasks in a specific order. You cannot directly include a
mapping in a task flow. You have to create a mapping configuration task and then include it in
task flow.
13. I get a validation error in expression when using un-connected lookup transformation?
When validating the a specific expression that refers to a un-connected lookup, you will get a
validation error. You can ignore this as long as the mapping level validation succeeds.
14. What is the difference between a mapping and a Mapping Configuration Task (MCT)?
A mapping defines a reusable data flow logic. Use the Informatica Cloud Mapping Designer to
configure mappings. In order to run a mapping as a task, you create a mapping configuration
task using MCT.
15. What is a parameterized mapping?
A mapping defines a data flow logic that you can use to create mapping configuration tasks.
To make the mappings reusable by parametezing the mapping. This provides additional
flexibility in how you can use the mapping. Parameters act as placeholders for information that
you define in the mapping configuration task. For example, you can use a parameter for a
source connection in a mapping, and then define the source connection when you configure the
task.
16. Can I create a task for a mapping using the API?
Yes, you can use the mttask resource POST request to create and update mapping configuration
task.
17. Why don’t I see a Source Qualifier in a mapping?
For users who have used the PowerCenter to create mappings, you would have noticed that
there is a source qualifier transformation is created when a source object is pulled into the
mapping.
In PowerCenter the source object contains only the metadata of the source and does not
contain the information about the physical location like server or database name. So a source
qualifier transformation is needed to associate the source to the connection object. Also
another function of the source qualifier is to convert the source specific data types into
Informatica data types. For example convert oracle varchar2 to String.
But in cloud mapping designer, instead of the source object, we create a source transformation
that combines the functionality of the storing the source metadata as well as storing the
physical information about the source by being associated with a connection.
18. Are the CMD mapping parameters same as PowerCenter parameters?
While there are similarities between the parameters in PowerCenter and CMD, there are key
differences that make the parameters provided in CMD more powerful.
In PowerCenter mapping parameter represents a constant value that can change between mapping
runs, such as connections, source file directories, source table names . The value for the parameters
is provided when the session is run using a parameter file.
In CMD, parameter is a placeholder for a value or values in a mapping. While you can create
parameters for the PowerCenter use cases mentioned earlier, you can also create parameters for
the logical aspects of a data flow. You define the value of the parameter when you configure the
mapping configuration task.
For example,

You can parameterize the incoming fields into a transformation based on data type or
pattern

Parameterize the field mapping to the target from the previous transformation
So, using the parameters in CMD, we can create generic mappings for slowly changing dimension
mapping that can be used with any OLTP source and DW target. But creating this type of generic
mapping templates are not possible using PowerCenter parameters.
19. What can be parameterized in a mapping?
You can create different types of parameters. The type of parameter indicates how and where
you can use the parameter.
The different types of parameters are
Parameter
Type
Description
Connection
Represents a connection
Represents a data object, such as a source table or source
Data object
file
Expression
Represents an expression
String
Represents a string value to be used as entered
Field
Represents a field
Represents field mappings for the task. You can create a
Field mapping
full or partial field mapping.
Parameter
Type
Connection
Connection
Connection
Connection
Data object
Data object
Data object
Expression
Expression
Expression
String
Mapping Location where the parameter can be used
Source connection
Lookup connection
Mapplet connection
Target connection
Source object
Lookup object
Target object
Full expression in the Expression transformation
Full join condition in the Joiner transformation
Full lookup condition in the Lookup transformation
All transformations: Field rule bulk rename by pattern
String
String
String
Field
Field
Field
Field mapping
Field mapping
All transformations: Field name for the Named Fields field
selection criteria
Filter condition value in the Filter transformation
Joiner condition value in the Joiner transformation
Field in a filter condition in the Filter condition
Field in a join condition in the Joiner transformation•
Field in a lookup condition in the Lookup transformation
Field mapping in the Mapplet transformation
Field mapping in the Target transformation
20. How do I create a Salesforce lookup?
You can create a Saleforce lookup by using the lookup transformation. In the lookup transformation
configure the Lookup Object Details to point a Salesforce connection and object.
21. What are expression variables?
You can use variable ports in an expression or aggregator to temporarily store data.
Unique features of variable are
 It can be referenced in other variable or output ports – so you can break down complex
formulae into multiple steps by using variable and storing the value of each step in a
variable
 The value of the variable port is persistent across rows – The value assigned to a variable
port is stored and is available when the variable is referenced in the subsequent source
row before it is re-evaluated.
To take advantage of this, the variable used to store the value from previous row should
be referenced in another variable which appears before the display order. This is
because; the application evaluates all input ports first. The application
evaluates variable ports after input ports based on the display order. The application
evaluates the output ports last
For example, a source file contains the following rows
State
California
California
California
Hawaii
Hawaii
New Mexico
New Mexico
New Mexico
The output required is
State
California
California
California
Hawaii
Hawaii
New Mexico
New Mexico
New Mexico
New State
flag
Y
N
N
Y
N
Y
N
N
The Expression transformation has the following ports:
Port
Port Type
Passthrough
State
Expression
n/a
v_New_State_Flag
Variable
IIF
(PREVIOUS_STATE =
STATE, 'N', 'Y')
v_Previous_State
Variable
State
out_New_State_Flag Output
You might
v_New_State_Flag
use variables to complete the following tasks:

Temporarily store data.

Simplify complex expressions.

Store values from prior rows.

Compare values.
Description
The name of a state.
The new_State_flag for the current State. When the
value of the current State column is the same as the
Previous_State column, the application sets the
variable to 'N'. Otherwise, it sets the New_State_Flag
to 'Y'.
The value of the State column in the previous row.
When the application processes a row, it moves the
State value to Previous_State.
The application returns New_State_Flag for each
row.
22. How does a Lookup transformation work?
The Lookup transformation retrieves a value from the lookup object based on a value in the
source. For example, if the source has an employee ID, you can retrieve the employee name
from the lookup object.
You have to configure the lookup condition, to compare the employee ID from the data flow
with employee ID values in the lookup object.
The application builds a cache in memory when it processes the first row of source data. The
application stores condition values in the index cache and output values in the data cache. The
application queries the cache for each row that enters the transformation. If the data does not
fit in the memory cache, the application stores the overflow values in the cache files.
23. What applications can I create a lookup for?
You can perform a lookup on files, database tables, Salesforce, and SAP tables.