Re: [PERFORM] Outer joins and equivalence

Simon Riggs <[EMAIL PROTECTED]> writes: > I have a complex query where making a small change to the SQL increases > run-time by > 1000 times. > The first SQL statement is of the form > A JOIN B ON (a.id = b.id) LEFT JOIN C ON (a.id = c.id) > and the second is like this > A JOIN B ON (a.id = b.

Re: [PERFORM] I/O on select count(*)

On Mon, 2008-05-26 at 11:36 -0400, Tom Lane wrote: > "Heikki Linnakangas" <[EMAIL PROTECTED]> writes: > > Decibel! wrote: > >> Also, Simon and Tom had an idea at PGCon: Don't set hint-bits in the > >> back-end if the page isn't already dirty. > > > Or even better: set the hint-bits, but don't d

[PERFORM] Outer joins and equivalence

I have a complex query where making a small change to the SQL increases run-time by > 1000 times. The first SQL statement is of the form A JOIN B ON (a.id = b.id) LEFT JOIN C ON (a.id = c.id) and the second is like this A JOIN B ON (a.id = b.id) LEFT JOIN C ON (b.id = c.id) the only differen