Re: EXPLAIN times

Afra <aa4(at)cse(dot)buffalo(dot)edu> writes:
> The postgres version for each box is 7.2.1.

Upgrading to 7.2.3 would be a good idea (it won't effect this problem,
it's just a good idea in general).

> These are the EXPLAIN results on DB1:
>
> NOTICE: QUERY PLAN:
>
> Merge Join (cost=152183.00..271426.66 rows=9416137 width=105)
> -> Sort (cost=141295.60..141295.60 rows=613709 width=69)
> -> Seq Scan on ord_contact_name (cost=0.00..18568.09
> rows=613709 width=69)
> -> Sort (cost=10887.40..10887.40 rows=3069 width=36)
> -> Index Scan using dv_job_number_ord_dv_job_num_ke on
> ord_dv_job_num (cost=0.00..10709.67 rows=3069 width=36)
>
> And the EXPLAIN results on DB2:
>
> NOTICE: QUERY PLAN:
>
> Nested Loop (cost=0.00..9.91 rows=1 width=90)
> -> Index Scan using dv_job_number_ord_dv_job_num_ke on
> ord_dv_job_num (cost=0.00..3.89 rows=1 width=40)
> -> Index Scan using ord_obj_guid_ord_contact_name_k on
> ord_contact_name (cost=0.00..6.01 rows=1 width=50)

Have you run VACUUM ANALYZE on both databases recently? (if you
haven't, do so). The statistics for DB1 look bizarrely incorrect, so
I'd suspect that updating them will fix the problem.

Is PostgreSQL configured in the same way on both systems?

Cheers,

Neil

--
Neil Conway <neilc(at)samurai(dot)com> || PGP Key ID: DB3C29FC