Re: What needs to be done for real Partitioning? - Mailing list pgsql-performance

From Tom Lane
Subject Re: What needs to be done for real Partitioning?
Date
Msg-id 14172.1111359709@sss.pgh.pa.us
Whole thread Raw
In response to Re: What needs to be done for real Partitioning?  ("Stacy White" <harsh@computer.org>)
Responses Re: What needs to be done for real Partitioning?
Re: What needs to be done for real Partitioning?
List 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

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