On 03/03/2011 05:29 AM, obamaba...@e1.ru wrote:
I use pgsql 9.0.3 and I know that postgresql tries to use the fields in
indexes instead of the original table if it possible
But when I run
SELECT COUNT(id) FROM tab
or
SELECT COUNT(*) FROM tab
where there "id" is PRIMARY KEY and there are other indexes there I get
execution plan that doesnt use any indexes, but sequentab scanning the
original table.
"Aggregate (cost=38685.98..38685.99 rows=1 width=0)"
" -> Seq Scan on tab (cost=0.00..36372.38 rows=925438 width=0)"
Why is it so?
See here:
http://wiki.postgresql.org/wiki/FAQ#Why_is_.22SELECT_count.28.2A.29_FROM_bigtable.3B.22_slow.3F
---
Paul
--
Adrian Klaver
adrian.kla...@gmail.com
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
