Using the Custom Result Processor API

Data-aware procedures use a separate result processor to merge the procedure results from multiple GemFire XD members. You can use the default GemFire XD result processor when basic concatenation of the results are required.

Default Result Processor describes how the default processor works.

For more complex use cases, such as sorting, merging, or joining the results from different servers, you must implement your own result processor to customize the merge behavior. A custom processor can be used to modify a procedure's OUT parameters and result sets before emitting the results to a client.

The sections that follow describe how to use the GemFire XD result processor API to implement your own custom result processor. Sample code is provided for a result processor that performs comparison-based sorting (merge sort) of data-aware procedure results.