Re: Index non-usage problem in 8.2.9

Joseph S <jks@selectacast.net> writes:
> Actually sacode is an int2.

Ah.  8.2 is not very good at proving cross-type predicate conditions,
because it lacks the concept of an operator family.  You need to declare
the index this way:

create index d2i on d2 (sgcode, sacode)
  WHERE sacode IS NOT NULL AND sacode > 0::int2;

(As previously noted, you don't really need the IS NOT NULL part of the
condition, but that isn't what's causing the problem here.)

            regards, tom lane