RE : RE : Increase performance of a UNION query that thakes 655.07 msec to be runned ?

> On Fri, 6 Feb 2004, Bruno BAGUETTE wrote:
>
> > > In addition to what Tom said, the row estimates look suspiciously
> > > default. You mention vacuuming, but do you ever analyze
> > > the tables?
> >
> > I run VACUUM FULL ANALYZE with the postgres user on all the
> > PostgreSQL
> > databases on the server, twice a day, sometimes more.
>
> Wierd, because you're getting 1000 estimated on both people
> and organizations. What does pg_class have to say about
> those two tables?

I'm sorry but I think that I misunderstand you. Are you telling me that
running VACUUM FULL ANALYZE is weird ? Or do you mean another thing ?

Finally, I've found another way : I've build a MATERIALIZED VIEW that
stores the initial (CHAR(1) of both people and organizations, with an
index on that column. I get excellent results :

Unique (cost=0.00..290.34 rows=1117 width=5) (actual time=0.52..267.38
rows=39 loops=1)
-> Index Scan using idx_mview_initials on mview_contacts
(cost=0.00..262.42 rows=11167 width=5) (actual time=0.51..172.15
rows=11167 loops=1)
Total runtime: 267.81 msec
(3 rows)

So, that's a better runtime :-)

Thanks for your help :-)

-------------------------------------
Bruno BAGUETTE - pgsql-ml(at)baguette(dot)net