serverdb=# set enable_hashjoin=off;
SET
serverdb=# explain select count(*) as y0_ from SARS_ACTS this_ inner join SARS_ACTS_RUN tr1_ on this_.SARS_RUN_ID=tr1_.ID where tr1.ALGORITHM='SMAT';

                                                    QUERY PLAN
--------------------------------------------------------------------------------------------------------------------------
Aggregate  (cost=7765563.69..7765563.70 rows=1 width=0)
      Nested Loop  (cost=0.00..7765555.35 rows=3336 width=0)
         -> Index Scan using idx_sars_acts_run_algorithm on sars_acts_run tr1_  (cost=0.00..44.32 rows=650 width=8)
              Index Cond:  ((algorithm)::text = 'SMAT'::text)
         -> Index Scan using idx_sars_acts_run_id_end_time on sars_acts this_  (cost=0.00..11891.29 rows=4452 width=8)
              Index Cond:  (SARS_RUN_ID=tr1_.ID)
(6 rows)

serverdb=# \timing
TIming is on.

serverdb=# select count(*) as y0_ from SARS_ACTS this_ inner join SARS_ACTS_RUN tr1_ on this_.SARS_RUN_ID=tr1_.ID where tr1.ALGORITHM='SMAT';
 y0_
------
1481710
(1 row)

Time: 85069.416 ms < 1.4 minutes <-- not great, but much better!

Subsequently, runs in the milliseconds once cached.

But what negative impact is disabling hash joins?

Sorry, I just executed the explain without the analyze, I'll send out the "explain analyze" next reply.

thanks

Freddie