Re: Massive memory use for star query

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Mark Kirkwood <mark(dot)kirkwood(at)catalyst(dot)net(dot)nz>
Cc: pgsql-bugs(at)postgresql(dot)org
Subject: Re: Massive memory use for star query
Date: 2011-04-15 16:43:01
Message-ID: 25522.1302885781@sss.pgh.pa.us
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-bugs

Mark Kirkwood <mark(dot)kirkwood(at)catalyst(dot)net(dot)nz> writes:
> I've recently seen examples of star-like queries using vast amounts of
> memory in one of our production systems. Here's a simplified example
> using synthetic data (see attached to generate if desired):

> SET geqo_threshold = 14;
> SET from_collapse_limit = 14;
> SET join_collapse_limit = 14;

Well, if you're going to do the above, you should be expecting the
planner to eat a lot of memory. There is a reason why the default
values of those parameters are significantly lower than that ...

regards, tom lane

In response to

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Rikard Pavelic 2011-04-15 18:34:28 BUG #5982: recursive type crashes postgres
Previous Message Kevin Grittner 2011-04-15 15:14:36 Re: Massive memory use for star query