* Atri Sharma (atri.j...@gmail.com) wrote: > On Mon, May 27, 2013 at 3:41 PM, Ben Zeev, Lior <lior.ben-z...@hp.com> wrote: > > Do you have idea what may be the reason that PostgreSQL process consume > > more memory when there are more partial indexes on the DB table?
It might use a bit more, but it shouldn't be excessive.. What, exactly,
are you seeing and would it be possible for you to provide a repeatable
test case with a small-ish set of data?
> Well, I am not too sure, but indexes always take up more space, so if
> your backend has a lot of indexes, it will cause the process to
> consume more memory.
Indexes require additional disk space, certainly. Having a lot of
indexes, by itself, shouldn't seriously increase memory usage.
> Indexes should be used with care, as too many indexes can cause a
> memory overhead,which can cause performance degradations.
This is not generally a reason to avoid indexes. Indexes require more
disk space and must be kept up to date, making them expensive to
maintain due to increased disk i/o. Building an index uses as much
memory as it's allowed to- it uses maintenance_work_mem to limit itself.
Thanks,
Stephen
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