contrib/plantuner - enable PostgreSQL planner hints

Hi there,

this is an announcement of our new contribution module for PostgreSQL -
Plantuner - enable planner hints
(http://www.sai.msu.su/~megera/wiki/plantuner).

Example:

=# LOAD 'plantuner';
=# create table test(id int);
=# create index id_idx on test(id);
=# create index id_idx2 on test(id);
=# \d test
      Table "public.test"
  Column |  Type   | Modifiers
--------+---------+-----------
  id     | integer |
Indexes:
     "id_idx" btree (id)
     "id_idx2" btree (id)
=# explain select id from test where id=1;
                               QUERY PLAN
-----------------------------------------------------------------------
  Bitmap Heap Scan on test  (cost=4.34..15.03 rows=12 width=4)
    Recheck Cond: (id = 1)
    ->  Bitmap Index Scan on id_idx2  (cost=0.00..4.34 rows=12 width=0)
          Index Cond: (id = 1)
(4 rows)
=# set enable_seqscan=off;
=# set plantuner.forbid_index='id_idx2';
=# explain select id from test where id=1;
                               QUERY PLAN
----------------------------------------------------------------------
  Bitmap Heap Scan on test  (cost=4.34..15.03 rows=12 width=4)
    Recheck Cond: (id = 1)
    ->  Bitmap Index Scan on id_idx  (cost=0.00..4.34 rows=12 width=0)
          Index Cond: (id = 1)
(4 rows)
=# set plantuner.forbid_index='id_idx2,id_idx';
=# explain select id from test where id=1;
                                QUERY PLAN
-------------------------------------------------------------------------
  Seq Scan on test  (cost=10000000000.00..10000000040.00 rows=12 width=4)
    Filter: (id = 1)
(2 rows)



     Regards,
         Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg@sai.msu.su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83