Re: capturing/viewing sort_mem utilization on a per query basis

On Wed, 02 Feb 2005 12:58:49 -0500, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Lonni J Friedman <netllama(at)gmail(dot)com> writes:
> > On Wed, 02 Feb 2005 12:13:59 -0500, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >> Hmm, looks like a hash join ran out of memory. What PG version is this
> >> again, and what do you have sort_mem set to? Can you show an EXPLAIN
> >> for the query that is failing like this?
>
> > I've attached the explain for the query that is blowing up.
>
> One of the three Hash steps must be absorbing a whole lot more rows than
> the planner is expecting, but all of them look like fairly
> straightforward estimation situations:
>
> -> Hash (cost=108.96..108.96 rows=28 width=24)
> -> Index Scan using mntr_subscr_usrevt on mntr_subscription sfmain_monitoringsubscriptio0 (cost=0.00..108.96 rows=28 width=24)
> Index Cond: (((user_id)::text = 'user1187'::text) AND ((event_operation)::text = 'update'::text))
>
> -> Hash (cost=701.44..701.44 rows=34444 width=24)
> -> Seq Scan on field_value tracker_artifact_group0 (cost=0.00..701.44 rows=34444 width=24)
>
> -> Hash (cost=5.74..5.74 rows=1 width=80)
> -> Index Scan using project_path on project tracker_artifact_extension_f1 (cost=0.00..5.74 rows=1 width=80)
> Index Cond: (("path")::text = 'projects.meeting_broker_v3'::text)
> Filter: ((("path")::text = 'projects.meeting_broker_v3'::text) OR (("path")::text ~~ 'projects.meeting_broker_v3.%'::text))
>
> Perhaps one of these tables hasn't been vacuumed/analyzed and is way

I'm doing a 'vacuumdb -a -z' every 15 minutes, and a full vacuum once/day.

> bigger than the planner thinks? Can you check into how many rows
> actually meet the identified conditions?

I'm afraid i'm not clear on what i'm supposed to be checking here.
Which conditions should I be looking at? thanks.

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L. Friedman netllama(at)gmail(dot)com
LlamaLand http://netllama.linux-sxs.org