Advanced

This tab allows you to specify the following:

• Execution Mode. The stage can execute in parallel mode or sequential mode. In parallel mode the 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 data 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 to Propagate by default, this sets or clears the partitioning in accordance with what the previous stage has set. You can also select Set or Clear. If you select Set, the stage will request that the next stage preserves the partitioning as is.
• Legacy null processing. Use this option to return to earlier releases of IBM DataStage null handling. In older releases, null values in input rows had to be explicitly handled by function calls if any processing was carried out on that row. Otherwise rows that contained nulls were dropped (this did not apply where the row was passed through the Transformer with no processing). If you do not select the Legacy null processing option, then a null in the input column used in the derivation causes a null to be output.
• Abort on unhandled null. Set this option to force the job to stop when the transformer encounters a null value in a row. You can then locate the row and column that contained the null from the job log. If you set this option together with the Legacy null processing option, then any nulls that occur in input columns used in output column derivations that are not explicitly handled by the expression cause the job to stop. If you set the Abort on unhandled null option without setting the Legacy null processing option, then only operations such as attempting to set a non-nullable column to null cause the job to stop.
• Maximum log reject messages. Whenever a row is rejected because it contains a null value, a warning is written to the job log. Potentially there could be a lot of messages, so you can use the Maximum log reject messages option to set limits. By default, up to 50 messages per partition are allowed, but you can increase or decrease this, or set it to -1 to allow unlimited messages.