On Wed, Sep 27, 2017 at 9:56 AM, Jesper Pedersen <jesper.peder...@redhat.com> wrote: > Maybe an initial proof-of-concept could store the hash of the first column > (col1) plus the hash of all columns (col1, col2, col3) in the index, and see > what requirements / design decisions would appear from that.
I thought about that sort of thing yesterday but it's not that simple. The problem is that the hash code isn't just stored; it's used to assign tuples to buckets. If you have two hash codes, you have to pick one of the other to use for assigning the tuple to a bucket. And then if you want to search using the other hash code, you have to search all of the buckets, which will stink. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
