Re: table/index options | was: [HACKERS] COUNT(*) and index-only scans

2011-10-11 Thread Robert Haas
On Mon, Oct 10, 2011 at 3:16 PM, Cédric Villemain cedric.villemain.deb...@gmail.com wrote: 2011/10/10 Robert Haas robertmh...@gmail.com: On Mon, Oct 10, 2011 at 1:36 PM, Kevin Grittner kevin.gritt...@wicourts.gov wrote: That gives you an index-only scan; but without the WHERE clause it uses

table/index options | was: [HACKERS] COUNT(*) and index-only scans

2011-10-10 Thread Cédric Villemain
2011/10/10 Robert Haas robertmh...@gmail.com: On Mon, Oct 10, 2011 at 1:36 PM, Kevin Grittner kevin.gritt...@wicourts.gov wrote: That gives you an index-only scan; but without the WHERE clause it uses a seq scan.  I think it's mainly a matter of doing enough benchmarks to figure out how best