--- Tom Lane <[EMAIL PROTECTED]> wrote: > You don't need to post questions four times ;-) > > Heni Lolov <[EMAIL PROTECTED]> writes: > > I have folowing table > > > create table usno( > > reg_id int2, > > id int2, > > ra int4, > > de int4, > > mag_r int2, > > mag_b int2 > > ); > > > I make indexes in this order: > > create index usno_drm_r on gsc_act(de,ra,mag_r); > > create index usno_drm_b on gsc_act(de,ra,mag_b); > > > the problem is: > > when I search on "de","ra" and "mag_b" or "de", > "ra" > > and "mag_r" Postgres uses always "usno_drm_r". > > If I create the indexes in reversed order > > "usno_drm_b" is always used. > > I bet that it's only using the first two columns of > the index, > so that it doesn't really matter which index is > used. Are you > being careful to cast the values compared to mag_r > or mag_b to > int2? "mag_r = 42" isn't indexable because 42 is an > int4.
I am sure that the values are int2 and there is no casting when I am using psql to examine this. > > regards, tom lane __________________________________________________ Do You Yahoo!? Send your FREE holiday greetings online! http://greetings.yahoo.com ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
