Re: BUG #5946: Long exclusive lock taken by vacuum (not full)
Robert Haas <robertmhaas@gmail.com>
From: Robert Haas <robertmhaas@gmail.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Greg Stark <gsstark@mit.edu>, Alvaro Herrera <alvherre@commandprompt.com>, Christopher Browne <cbbrowne@gmail.com>, Maxim Boguk <maxim.boguk@gmail.com>, pgsql-bugs <pgsql-bugs@postgresql.org>
Date: 2011-03-28T18:20:55Z
Lists: pgsql-bugs
On Mon, Mar 28, 2011 at 12:29 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote: > Robert Haas <robertmhaas@gmail.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