Re: [HACKERS] Problem with complex query

Hi!

On Wed, 24 Feb 1999, Tom Lane wrote:
> What version are you running?  Also, does it act the same if you try to

   6.4.2 on Sparc-solaris2.5.1

> EXPLAIN that same query?  If EXPLAIN fails then the problem is in the
> plan/optimize stage, not actual execution of the query.

   EXPLAIN works fine:

EXPLAIN SELECT DISTINCT p.subsec_id
   FROM central cn, shops sh, districts d, positions p
      WHERE cn.shop_id = sh.shop_id AND sh.distr_id = d.distr_id
      AND   d.city_id = 2 AND cn.pos_id = p.pos_id
      AND   cn.date_i >= current_date - '7 days'::timespan
;
NOTICE:  QUERY PLAN:

Unique  (cost=0.00 size=0 width=0)
  ->  Sort  (cost=0.00 size=0 width=0)
        ->  Nested Loop  (cost=0.00 size=1 width=16)
              ->  Nested Loop  (cost=0.00 size=1 width=12)
                    ->  Merge Join  (cost=0.00 size=1 width=8)
                          ->  Seq Scan  (cost=0.00 size=0 width=0)
                                ->  Sort  (cost=0.00 size=0 width=0)
                                      ->  Seq Scan on districts d
(cost=0.00 size=0 width=2)
                          ->  Seq Scan  (cost=0.00 size=0 width=0)
                                ->  Sort  (cost=0.00 size=0 width=0)
                                      ->  Seq Scan on shops sh  (cost=0.00
size=0 width=6)
                    ->  Seq Scan on central cn  (cost=0.00 size=0 width=4)
              ->  Seq Scan on positions p  (cost=0.00 size=0 width=4)

EXPLAIN

Oleg.
---- 
    Oleg Broytmann     http://members.xoom.com/phd2/     phd2@earthling.net
           Programmers don't die, they just GOSUB without RETURN.