Lars Aksel Opsahl <lars.ops...@nibio.no> writes:
> In this example I have two tables one with 4 billion rows and another with
> 50000 rows and then I try to do a standard simple join between this two
> tables and this takes 397391 ms. with this SQL (the query plan is added is
> further down)
This particular query would work a lot better if you had an index on
nora_bc25_observation (point_uid_ref, epoch), ie both join columns
in one index. I get the impression that that ought to be the primary
key of the table, which would be an even stronger reason to have a
unique index on it.
regards, tom lane
--
Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-performance
