Re: equivalence class not working?

Fine. The rest documentation says:" For now, the test only uses
restrictionclauses (those in restrictinfo_list). --Nels, Dec '92",
however, I
understand it as being overridden by the
followup, which is:"XXX as of 7.1, equivalence class info *is* available.
Consider
improving this code as foreseen by Nels."

Therefore, equivalence class should be detected and used for index
selection... or anyone
could tell me if after 7.1 Postgresql has determined not to use equi-join
for index selection...

On 1/16/06, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>
> uwcssa <uwcssa(at)gmail(dot)com> writes:
> > I am using postgres 8.1. In indxpath.c, it says " Note: if Postgres
> tried
> > to optimize queries by forming equivalence
> > classes over equi-joined attributes (i.e., if it recognized that
> > aqualification such as "where
> > a.b=3Dc.d and a.b=3D5" could make use of
> > an index on c.d), then we could use that equivalence class info here
> with
> > joininfo_list to do more complete tests for the usability
> > of a partial index. ..... XXX as of 7.1, equivalence class info *is*
> > available."
>
> Are you deliberately ignoring the rest of the comment?
>
> regards, tom lane
>