Re: More thoughts about planner's cost estimates - Mailing list pgsql-hackers

From Tom Lane
Subject Re: More thoughts about planner's cost estimates
Date
Msg-id 2579.1149458946@sss.pgh.pa.us
Whole thread Raw
In response to Re: More thoughts about planner's cost estimates  (Greg Stark <gsstark@mit.edu>)
Responses Re: More thoughts about planner's cost estimates  (Hannu Krosing <hannu@skype.net>)
Re: More thoughts about planner's cost estimates  (Jim Nasby <jnasby@pervasive.com>)
List pgsql-hackers
Greg Stark <gsstark@mit.edu> writes:
> Hannu Krosing <hannu@skype.net> writes:
>> Ühel kenal päeval, L, 2006-06-03 kell 10:43, kirjutas Jim Nasby:
>>> Might also be worth adding analyze delay settings, ala  
>>> vacuum_cost_delay.

ANALYZE already respects the vacuum delay settings.

>> Actually we should have delay settings for all potential
>> (almost-)full-scan service ops, - VACUUM, ANALYSE, CREATE INDEX, ADD
>> CONSTRAINT, maybe more - so that there would be better chances of
>> running those on busy databases without disastrous effects.

> What about UPDATE and DELETE and for that matter SELECT?

This seems pretty silly.  The point of the delay stuff is to prevent
background maintenance operations from eating an unreasonable share
of resources compared to foreground queries.  I don't see why you'd
put delays into queries --- if your machine is loaded, it's loaded.

I think the existing features are sufficient in this line and that
doing more is just adding complexity for complexity's sake.
        regards, tom lane


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