Re: index usage
Tom Lane <tgl@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
To: "scott.marlowe" <scott.marlowe@ihs.com>
Cc: Stephan Szabo <sszabo@megazone.bigpanda.com>, brad-pgperf@duttonbros.com, pgsql-performance@postgresql.org
Date: 2004-04-28T16:41:40Z
Lists: pgsql-performance
"scott.marlowe" <scott.marlowe@ihs.com> writes: > There are tons of hints that it works this way in how they're written, but > nothing that just comes out and says that with pgsql's mvcc > implementation, an index scan still has to hit the pages that contain the > tuples, so often in pgsql a seq scan is a win where in other databases and > index scan would have been a win? > If not, where would I add it if I were going to write something up for the > docs? Just wondering... AFAIR the only place in the docs that mentions seqscan or indexscan at all is the discussion of EXPLAIN in "Performance Tips". Perhaps a suitably-enlarged version of that section could cover this. regards, tom lane