The Asynchronous Script Component
As we discussed in previous chapters, Data Flow transformations are categorized into two categories based on their synchronization behavior: Synchronous and Asynchronous.
Synchronous Transformations process each input row, generate an output row at the same time, and then go to the next row. Asynchronous transformations stack incoming data and generate output based on some input records. An example of synchronous transformation is a Derived column, and an example of asynchronous transformation is Sort, because all rows have to be accumulated in order to sort them.
It's obvious that synchronous transformations are much better in terms of performance as compared to asynchronous transformations, but there are some cases where the only solution is an asynchronous transform.
The SSIS Script Component, when used in transformations, can act in both a synchronous and an asynchronous manner. In this recipe, we have a special type of input, which has its data in four...