Block Picker and Pass Controller

The block picker and pass controller define how the blocking query is executed during the match process. By default, the matching process is executed in multiple stages. Each configured block that defines query criteria is executed and evaluated separately (each query block execution and evaluation is referred to as a match pass). After a block is evaluated, the pass controller determines whether the results found are sufficient or matching should continue by performing another match pass.

The block picker chooses the block definition to use for each match pass. Block definitions define the criteria for each query that checks the database for a subset of the records to be used for matching. The block picker has access to the match results from previous match passes, as well as lists of applicable block definitions that have been executed and of those that have not been executed.