Difference stage: Stage tab (DataStage)
The Difference Stage tab enables you to control aspects of the Difference stage.
Double-click the stage to open the stage properties panel. The Properties section lets you specify what the stage does. The Advanced tab allows you to specify how the stage executes. The Link Ordering section allows you to specify which input link carries the before data set and which the after data set.
Difference Keys section
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
this dependent property:
- Case Sensitive
- Use this to 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.
Difference Values section
Set this to True to indicate that any columns not designated as difference key columns are value columns.
- All non-key columns are values
- It is False by default. The property has this dependent property:
The following table lists the other properties and their attributes.
Category/Property | Values | Default | Mandatory? | Repeats? | Dependent of |
---|---|---|---|---|---|
Difference Keys/Key | Input Column | N/A | Y | Y | N/A |
Difference Keys/Case sensitive | True/False | True | N | N | Key |
Difference Values/All non-key columns are values | True/False | False | Y | N | N/A |
Difference Values/Case sensitive | True/False | True | N | N | All non-Key Columns are Values (when true) |
Options/Insert code | number | 1 | N | N | N/A |
Options/Deleted code | number | 2 | N | N | N/A |
Options/Tolerate unsorted inputs | True/False | False | N | 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 | False | N | N | N/A |
Options/copy code | number | 0 | N | N | N/A |
Options/Edit code | number | 3 | N | N | N/A |
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 0.
Delete 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 1.
Advanced
This section allows you to specify the following:
- 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 section. 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 Set by default. You can explicitly select Set or Clear. Select Set to request the next stage should attempt to maintain the partitioning.