Re: performance using table partitions in Postgres 8.2.6

A Dilluns 07 Abril 2008, Janet Jacobsen va escriure:
> no. of partitions constraint_exclusion off constraint_exclusion on
> 2 0.597 ms 0.427 ms
> 4 0.653 ms 0.414 ms
> 8 0.673 ms 0.654 ms
> 16 1.068 ms 1.014 ms
> 32 2.301 ms 1.537 ms
>
> I expected that the query time would decrease as the number of
> partitions increases, but that's not what I am seeing. I get better
> results (0.29 ms) if I simply index DMID and don't use the partitions.

I see really small times here so probably the overhead that partitioning
imposes isn't worth yet. Maybe with 50M rows it'll help, you could try
feeding those 50M tuples and test again.

--
Albert Cervera Areny
Dept. Informàtica Sedifa, S.L.

Av. Can Bordoll, 149
08202 - Sabadell (Barcelona)
Tel. 93 715 51 11
Fax. 93 715 51 12

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