Tom Lane wrote:
Hardly surprising --- a search on the index's lowest-order column would require scanning practically all of the index. (If you think about the ordering of the index entries you'll see why.) If this is a typical query then you need a separate index on transaction_time_commit.
Yes, actually I just moved transaction_time_commit column to the begining of the index, since, most of the time I run queries based on transaction_time_commit and then transaction_client_id and transaction_destination_id.
The fine manual goes into some detail about how to design indexes; http://www.postgresql.org/docs/8.3/static/indexes.html particularly 11.3, 11.5.
I see it now. I read the manual concerning CREATE INDEX command, and there is no mention of multicolumn indices, did not notice Note that points to Chapter 11.
Mike -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
