Re: Postgres-7.0.2 optimization question

Post the query you're using, there may be a way to rewrite it to use the
index.  I've found this to be true on all kinds of DBMSs.

--
Adam Ruth
InterCation, Inc.
www.intercation.com


""Igor V. Rafienko"" <igorr@ifi.uio.no> wrote in message
news:Pine.SOL.4.21.0010131345100.23627-100000@vigrid.ifi.uio.no...
>
>
> Hi,
>
>
> I've got a slight optimization problem with postgres and I was hoping
> someone could give me a clue as to what could be tweaked.
>
> I have a couple of tables which contain little data (around 500,000 tuples
> each), and most operations take insanely long time to complete. The
> primary keys in both tables are ints (int8, iirc). When I perform a delete
> (with a where clause on a part of a primary key), an strace shows that
> postgres reads the entire table sequentially (lseek() and read()). Since
> each table is around 200MB, things take time.
>
> I tried vacuumdb --analyze. It did not help. I tried creating an index on
> the part of the primary key that is used in the abovementioned delete. It
> did not help either.
>
> Has anyone encountered the same kind of problems before? In that case, has
> anyone found a solution? (the problem is that the DB can very fast get 20
> times larger (i.e. 10,000,000 tuples per table is a moderate size), and
> I'd rather not witness a delete that takes around 90 minutes (100,000
> tuples were deleted) more than once).
>
>
> TIA,
>
>
> ivr
> --
> Women wearing Wonder bras and low-cut blouses lose their right to
> complain about having their boobs stared at.
> "Things men wish women knew"
>
>