Re: AutoVacuum starvation from sinval messages

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Simon Riggs <simon@2ndQuadrant.com>
Cc: Jeff Janes <jeff.janes@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2012-11-08T23:23:46Z
Lists: pgsql-hackers
Simon Riggs <simon@2ndQuadrant.com> writes:
> On 8 November 2012 20:36, Jeff Janes <jeff.janes@gmail.com> wrote:
>> It does not seem outrageous to me that there would be real-world
>> conditions in which invalidations would be sent more than once a
>> minute over prolonged periods, so this total starvation seems like a
>> bug.

> Yes, its a bug, but do you really believe the above? In what cases?

It doesn't take a whole lot of DDL to provoke an sinval overrun, if
the recipient process is just sitting idle and not servicing the
messages.  I think Jeff's concern is entirely valid.

			regards, tom lane