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Re: BUG #5946: Long exclusive lock taken by vacuum (not full)

From: Robert Haas <robertmhaas(at)gmail(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Greg Stark <gsstark(at)mit(dot)edu>, Alvaro Herrera <alvherre(at)commandprompt(dot)com>, Christopher Browne <cbbrowne(at)gmail(dot)com>, Maxim Boguk <maxim(dot)boguk(at)gmail(dot)com>, pgsql-bugs <pgsql-bugs(at)postgresql(dot)org>
Subject: Re: BUG #5946: Long exclusive lock taken by vacuum (not full)
Date: 2011-03-28 18:20:55
Message-ID: AANLkTinvJgdKC=-ScG-DTELSQu4etYVwr=+NGkvyhKKo@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-bugs
On Mon, Mar 28, 2011 at 12:29 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> I think we've had a number of pieces of evidence that suggest that
>> extending 8kB at a time is too costly, but I agree with Greg that the
>> idea of extending an arbitrarily large table by 10% at a time is
>> pretty frightening - that could involve allocating a gigantic amount
>> of space on a big table.  I would be inclined to do something like
>> extend by 10% of table or 1MB, whichever is smaller.
>
> Sure, something like that sounds sane, though the precise numbers
> need some validation.

Yeah.

>> ... And a 1MB extension is probably also small enough
>> that we can do it in the foreground without too much of a hiccup.
>
> Less than convinced about this.

Well, I guess we can always try it and see.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company

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Next:From: Christopher BrowneDate: 2011-03-28 19:01:10
Subject: Re: BUG #5946: Long exclusive lock taken by vacuum (not full)
Previous:From: Tom LaneDate: 2011-03-28 18:15:39
Subject: Re: BUG #5950: backend terminating after altering table

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