Re: same plan, add 1 condition, 1900x slower - Mailing list pgsql-performance

Mitch Skinner wrote:
>
> The version with the condition is definitely doing more I/O.  The
> version without the condition doesn't read at all.
[snip]
>            relname           | relpages |  reltuples
> -----------------------------+----------+-------------
>  external_id_map             |   126883 | 1.55625e+07
>  external_id_map_primary_key |    64607 | 1.55625e+07
>  subject                     |       31 |        1186
>  subject_pkey                |       19 |        1186

Does external_id_map really have 15 million rows? If not, try a VACUUM
FULL on it. Be prepared to give it some time to complete.

--
   Richard Huxton
   Archonet Ltd