On Wed, Oct 10, 2012 at 9:13 PM, Korisk <Korisk@xxxxxxxxx> wrote: > -> Index Only Scan Backward using hashcheck_name_idx on public.hashcheck (cost=10000000000.00..10000398674.92 rows=25986792 width=32) It seems odd. Is it possible to look at the non default configuration? SELECT name, setting, reset_val FROM pg_settings WHERE setting <> reset_val; > (actual time=0.104..3785.767 rows=25990002 loops=1) > Output: name > Heap Fetches: 0 > Total runtime: 7452.509 ms > (6 rows) > > Благодаря шаманствам на: > http://www.sql.ru/forum/actualthread.aspx?tid=974484 > > 11.10.2012, 01:30, "Sergey Konoplev" <gray.ru@xxxxxxxxx>: >> On Wed, Oct 10, 2012 at 9:09 AM, Korisk <Korisk@xxxxxxxxx> wrote: >> >>> Hello! Is it possible to speed up the plan? >>> Sort (cost=573977.88..573978.38 rows=200 width=32) (actual time=10351.280..10351.551 rows=4000 loops=1) >>> Output: name, (count(name)) >>> Sort Key: hashcheck.name >>> Sort Method: quicksort Memory: 315kB >>> -> HashAggregate (cost=573968.24..573970.24 rows=200 width=32) (actual time=10340.507..10341.288 rows=4000 loops=1) >>> Output: name, count(name) >>> -> Seq Scan on public.hashcheck (cost=0.00..447669.16 rows=25259816 width=32) (actual time=0.019..2798.058 rows=25259817 loops=1) >>> Output: id, name, value >>> Total runtime: 10351.989 ms >> >> AFAIU there are no query optimization solution for this. >> >> It may be worth to create a table hashcheck_stat (name, cnt) and >> increment/decrement the cnt values with triggers if you need to get >> counts fast. >> >> -- >> Sergey Konoplev >> >> a database and software architect >> http://www.linkedin.com/in/grayhemp >> >> Jabber: gray.ru@xxxxxxxxx Skype: gray-hemp Phone: +14158679984 -- Sergey Konoplev a database and software architect http://www.linkedin.com/in/grayhemp Jabber: gray.ru@xxxxxxxxx Skype: gray-hemp Phone: +14158679984 -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
