Alvaro Herrera wrote:
Michael Paesold wrote:
Simon Riggs wrote:
On Thu, 2007-10-25 at 13:41 -0300, Alvaro Herrera wrote:
...
FWIW I disagree with cancelling just any autovac work automatically; in
my patch I'm only cancelling if it's analyze, on the grounds that if
you have really bad luck you can potentially lose a lot of work that
vacuum did. We can relax this restriction when we have cancellable
vacuum.
That was requested by others, not myself, but I did agree with the
conclusions. The other bad luck might be that you don't complete some
critical piece of work in the available time window because an automated
job kicked in.
Yeah, I thought we had agreed that we must cancel all auto vacuum/analyzes,
on the ground that foreground operations are usually more important than
maintenance tasks.
What this means is that autovacuum will be starved a lot of the time,
and in the end you will only vacuum the tables when you run out of time
for Xid wraparound.
Well, only if you do a lot of schema changes. In the previous
discussion, Simon and me agreed that schema changes should not happen on
a regular basis on production systems.
Shouldn't we rather support the regular usage pattern instead of the
uncommon one? Users doing a lot of schema changes are the ones who
should have to work around issues, not those using a DBMS sanely. No?
Best Regards
Michael Paesold
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