Re: Forcing the use of one index instead other.

"Edmundo Robles L." <erobles@sensacd.com.mx> writes:
> I have two index  with a same field into them like this:

> create index  numberfail on Events (numberfail);
> and
> create index failtype on  Events (numberfail,eventtype);

> then i ran explain analyze  and always  took the numberfail index but
i wish  the  failtype index;

Uh, why?  If you have the smaller index available it's hard to imagine
any sane reason not to use it.

> I though maybe  if  i delete the index numberfail could works, but i don't know  if the  another program
> will fail  if the numberfail index does'nt exists.

No, you can drop that one if you want to.  You might care to read the
fine manual about index design:
http://www.postgresql.org/docs/8.3/static/indexes.html

            regards, tom lane