On Thu, Jun 10, 2010 at 9:29 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> (moving to -hackers)
> On Wed, Jun 9, 2010 at 4:11 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>>> In going back through emails I had marked as possibly needing another
>>> look before 9.0 is released, I came across this issue again. As I
>>> understand it, analyze (or analyse) now collects statistics for both
>>> the parent individually, and for the parent and its children together.
>>> However, as I further understand it, autovacuum won't actually fire
>>> off an analyze unless there's enough activity on the parent table
>>> considered individually to warrant it. So if you have an empty parent
>>> and a bunch of children with data in it, your stats will still stink,
>>> unless you analyze by hand.
>>> Assuming my understanding of the problem is correct, we could:
>>> (a) fix it,
>>> (b) document that you should consider periodic manual analyze commands
>>> in this situation, or
>>> (c) do nothing.
>> The objections to (a) are that it might result in excessive ANALYZE work
>> if not done intelligently, and that we haven't got a patch ready anyway.
>> I would have liked to get to this for 9.0 but I feel it's a bit late
> I guess I can't really disagree with that. Should we try to document
> this in some way?
Proposed patch attached.
The Enterprise Postgres Company
In response to
pgsql-performance by date
|Next:||From: Magnus Hagander||Date: 2010-06-14 09:01:47|
|Subject: Re: Analysis Function|
|Previous:||From: Jayadevan M||Date: 2010-06-14 03:40:45|
|Subject: Re: Query about index usage|
pgsql-hackers by date
|Next:||From: Fujii Masao||Date: 2010-06-14 04:02:39|
|Subject: Re: Command to prune archive at restartpoints|
|Previous:||From: Robert Haas||Date: 2010-06-14 03:08:13|
|Subject: visibility map|