Change Capture stage: Stage tab (DataStage)

The Stage tab allows you to specify an optional description of the stage.

The Properties section lets you specify what the stage does. The Advanced section allows you to specify how the stage executes.

Properties

The following table lists the properties and their attributes:

Table 1. Properties
Category/Property	Values	Default	Mandatory?	Repeats?	Dependent of
Change Keys/Key	Input Column	N/A	Y	Y	N/A
Change Keys/Case Sensitive	True/False	True	N	N	Key
Change Keys/Sort Order	Ascending/ Descending	Ascending	N	N	Key
Change Keys/Nulls Position	First/Last	First	N	N	Key
Change Values/Value	Input Column	N/A	N	Y	N/A
Change Values/Case Sensitive	True/False	True	N	N	Value
Options/Change Mode	Explicit Keys & Values/All keys, Explicit values/Explicit Keys, All Values	Explicit Keys & Values	Y	N	N/A
Options/Log Statistics	True/False	False	N	N	N/A
Options/Drop Output for Insert	True/False	False	N	N	N/A
Options/Drop Output for Delete	True/False	False	N	N	N/A
Options/Drop Output for Edit	True/False	False	N	N	N/A
Options/Drop Output for Copy	True/False	True	N	N	N/A
Options/Code Column Name	string	N/A	N	N	N/A
Options/Copy Code	number	0	N	N	N/A
Options/Deleted Code	number	2	N	N	N/A
Options/Edit Code	number	3	N	N	N/A
Options/Insert Code	number	1	N	N	N/A

Change Keys category

Specifies the name of a difference key input column.

Key

This property can be repeated to specify multiple difference key input columns. You can use the Column Selection dialog box to select several keys at once if required. Key has the following dependent properties:

Case Sensitive
Use this property to specify whether each key is case sensitive or not. It is set to True by default; for example, the values "CASE" and "case" would not be judged equivalent.
Sort Order
Specify ascending or descending sort order.
Nulls Position
Specify whether null values should be placed first or last.

Change Value category

Value

Specifies the name of a value input column. You can use the Column Selection dialog box to select values at once if required . Value has the following dependent properties:

Case Sensitive
Use this to property to specify whether each value is case sensitive or not. It is set to True by default; for example, the values "CASE" and "case" would not be judged equivalent.

Options

Use the Options category to specify how the Change Capture stage operates.

Change mode: This mode determines how keys and values are specified. Choose Explicit Keys & Values to specify the keys and values yourself. Choose All keys, Explicit values to specify that value columns must be defined, but all other columns are key columns unless excluded. Choose Explicit Keys, All Values to specify that key columns must be defined but all other columns are value columns unless they are excluded.
Log statistics: This property configures the stage to display result information containing the number of input rows and the number of copy, delete, edit, and insert rows.
Drop output for insert: Specifies to drop (not generate) an output row for an insert result. By default, an output row is always created by the stage.
Drop output for delete: Specifies to drop (not generate) the output row for a delete result. By default, an output row is always created by the stage.
Drop output for edit: Specifies to drop (not generate) the output row for an edit result. By default, an output row is always created by the stage.
Drop output for copy: Specifies to drop (not generate) the output row for a copy result. By default, an output row is not created by the stage.
Code column name: Allows you to specify a different name for the output column carrying the change code generated for each record by the stage. By default the column is called change_code.
Copy code: Allows you to specify an alternative value for the code that indicates the after record is a copy of the before record. By default this code is 0.
Deleted code: Allows you to specify an alternative value for the code that indicates that a record in the before set has been deleted from the after set. By default this code is 2.
Edit code: Allows you to specify an alternative value for the code that indicates the after record is an edited version of the before record. By default this code is 3.
Insert code: Allows you to specify an alternative value for the code that indicates a new record has been inserted in the after set that did not exist in the before set. By default this code is 1.

Advanced

Specify the following advanced parameters:

Execution Mode. The stage can execute in parallel mode or sequential mode. In parallel mode the input data is processed by the available nodes as specified in the Configuration file, and by any node constraints specified on the Advanced tab. In Sequential mode the entire data set is processed by the conductor node.
Combinability mode. This is Auto by default, which allows IBM® DataStage® to combine the operators that underlie parallel stages so that they run in the same process if it is sensible for this type of stage.
Preserve partitioning. This is Propagate by default. It adopts Set or Clear from the previous stage. You can explicitly select Set or Clear. Select Set to request that next stage in the job should attempt to maintain the partitioning.