01e658fa74
Add hash functions for the record type as well as a hash operator family and operator class for the record type. This enables all the hash functionality for the record type such as hash-based plans for UNION/INTERSECT/EXCEPT DISTINCT, recursive queries using UNION DISTINCT, hash joins, and hash partitioning. Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://www.postgresql.org/message-id/flat/38eccd35-4e2d-6767-1b3c-dada1eac3124%402ndquadrant.com