[GENERAL] GEQO and KSQO problem.

From: "Natalya S(dot) Makushina" <mak(at)rtsoft(dot)msk(dot)ru>
To: "'Herouth Maoz'" <herouth(at)oumail(dot)openu(dot)ac(dot)il>, "pgsql-general(at)postgreSQL(dot)org" <pgsql-general(at)postgreSQL(dot)org>
Subject: [GENERAL] GEQO and KSQO problem.
Date: 1999-09-10 13:57:13
Message-ID: 01BEFBB5.E9F284F0@makushina.rtsoft.msk.ru
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

The query plan from your suggestion with regular expression is

Unique (cost=318.24 size=0 width=0)
-> Sort (cost=318.24 size=0 width=0)
-> Hash Join (cost=318.24 size=409 width=292)
-> Nested Loop (cost=310.65 size=131 width=268)
-> Seq Scan on clients (cost=126.07 size=87 width=256)
-> Index Scan using idxsclientidid1 on sotrud (cost=2.12 size=2271 width=12)
-> Hash (cost=0.00 size=0 width=0)
-> Seq Scan on prinadleg (cost=1.13 size=4 width=24)

It's look good, but it's better for our development team to have a simple query with 'OR'.
Unfortunely it's not better for Postgres optimizer. ;)
May be we try to istall an test Postgres v.6.5.1.

Thanks for your help, Natalya.

At 16:00 +0200 on 08/09/1999, Natalya S. Makushina wrote:

> i tried your query.
> This is query plan for select with union clause
> NOTICE: QUERY PLAN:
>...
> I think that it is too slow.
> May be optimizer is more intellect in Postgres v.6.5.1?
> I use Postgres v.6.4.2.

Yes, it's definitely supposed to be better.

By the way, if there are not supposed to be overlaps in the queries (that
is, a query about one email will never return the same tuple that was
returned by a query about another email), you should try UNION ALL. I think
it should remove the unique phases.

By the way, did you try the suggestion with the regular expression? What
was the cost of that?

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma

Browse pgsql-general by date

  From Date Subject
Next Message Oleg Broytmann 1999-09-10 14:24:09 Re: [HACKERS] Re: Query about postgres medical database
Previous Message Thomas Lockhart 1999-09-10 13:47:34 Re: Query about postgres medical database