Re: What needs to be done for real Partitioning?
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: "Stacy White" <harsh@computer.org>
Cc: "Alvaro Herrera" <alvherre@dcc.uchile.cl>, "PFC" <lists@boutiquenumerique.com>, "Josh Berkus" <josh@agliodbs.com>, pgsql-performance@postgresql.org
Date: 2005-03-20T23:01:49Z
Lists: pgsql-performance
"Stacy White" <harsh@computer.org> writes: > FWIW, we see large benefits from partitioning other than the ability to > easily drop data, for example: > - We can vacuum only the active portions of a table > - Postgres automatically keeps related records clustered together on disk, > which makes it more likely that the blocks used by common queries can be > found in cache > - The query engine uses full table scans on the relevant sections of data, > and quickly skips over the irrelevant sections > - 'CLUSTER'ing a single partition is likely to be significantly more > performant than clustering a large table Global indexes would seriously reduce the performance of both vacuum and cluster for a single partition, and if you want seq scans you don't need an index for that at all. So the above doesn't strike me as a strong argument for global indexes ... regards, tom lane