Re: creating of temporary table takes very long - Mailing list pgsql-performance

From Tom Lane
Subject Re: creating of temporary table takes very long
Date
Msg-id 13997.1145376597@sss.pgh.pa.us
Whole thread Raw
In response to Re: creating of temporary table takes very long  ("Sriram Dandapani" <sdandapani@counterpane.com>)
List pgsql-performance
"Sriram Dandapani" <sdandapani@counterpane.com> writes:
> Got an explain analyze output..Here it is
> "Seq Scan on c_chkpfw_hr_tr a  (cost=0.00..225975659.89 rows=11000
> width=136) (actual time=2.345..648070.474 rows=22001 loops=1)"
> "  Filter: (subplan)"
> "  SubPlan"
> "    ->  Bitmap Heap Scan on chkpfw_tr_hr_dimension b
> (cost=1474.64..10271.13 rows=1 width=0) (actual time=29.439..29.439
> rows=1 loops=22001)"
> "          Recheck Cond: (($0 = firstoccurrence) AND ($1 = sentryid_id)
> AND ($2 = node_id))"
> "          Filter: (($3 = customerid_id) AND (COALESCE($4, 0) =
> COALESCE(interface_id, 0)) AND (COALESCE($5, 0) = COALESCE(source_id,
> 0)) AND (COALESCE($6, 0) = COALESCE(destination_id, 0)) AND
> (COALESCE($7, 0) = COALESCE(sourceport_id, 0)) AND (COALESCE($8 (..)"
> "          ->  Bitmap Index Scan on chkpfw_tr_hr_idx1
> (cost=0.00..1474.64 rows=38663 width=0) (actual time=12.144..12.144
> rows=33026 loops=22001)"
> "                Index Cond: (($0 = firstoccurrence) AND ($1 =
> sentryid_id) AND ($2 = node_id))"
> "Total runtime: 648097.800 ms"

That's probably about as good a query plan as you can hope for given
the way the query is written.  Those COALESCE comparisons are all
unindexable (unless you make functional indexes on the COALESCE
expressions).  You might get somewhere by converting the EXISTS
to an IN, though.

            regards, tom lane

pgsql-performance by date:

Previous
From: "Tarabas (Manuel Rorarius)"
Date:
Subject: Re: [bulk] Re: Problem with LIKE-Performance
Next
From: "Sriram Dandapani"
Date:
Subject: Re: creating of temporary table takes very long