Hi, On 2017-08-03 17:43:44 -0400, Robert Haas wrote: > For me, the basic point here is that we need a set of hash functions > for hash partitioning that are different than what we use for hash > indexes and hash joins -- otherwise when we hash partition a table and > create hash indexes on each partition, those indexes will have nasty > clustering. Partitionwise hash joins will have similar problems. So, > a new set of hash functions specifically for hash partitioning is > quite desirable.
Couldn't that just as well solved by being a bit smarter with an IV? I doubt we want to end up with different hashfunctions for sharding, partitioning, hashjoins (which seems to form a hierarchy). Having a working hash-combine function, or even better a hash API that can continue to use the hash's internal state, seems a more scalable solution. Greetings, Andres Freund -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers