Configuring Custom Transformations as Blocking Transformations
Configuring Custom Transformations as Blocking Transformations
When you create a Custom transformation, the Designer enables the Inputs Must Block transformation property by default. This property affects data flow validation when you save or validate a mapping. When you enable this property, the Custom transformation is a blocking transformation. When you clear this property, the Custom transformation is not a blocking transformation.
Configure the Custom transformation as a blocking transformation when the external procedure code
must
be able to block input data.
You can configure the Custom transformation as a non-blocking transformation when one of the following conditions is true:
The procedure code does not include the blocking functions.
The procedure code includes two algorithms, one that uses blocking and the other that copies the source data to a buffer allocated by the procedure instead of blocking data. The code checks whether or not the Integration Service allows the Custom transformation to block data. The procedure uses the algorithm with the blocking functions when it can block, and uses the other algorithm when it cannot block. You might want to do this to create a Custom transformation that you use in multiple mapping configurations.
When the procedure blocks data and you configure the Custom transformation as a non-blocking transformation, the Integration Service fails the session.