Re: Is this a planner bug?
| От | Pavel Stehule |
|---|---|
| Тема | Re: Is this a planner bug? |
| Дата | |
| Msg-id | CAFj8pRDkgSwRb6fx4N1k7n9gFqAResim+GDrxU1o9TUPw+0AkQ@mail.gmail.com обсуждение исходный текст |
| Ответ на | Is this a planner bug? (Torsten Förtsch <torsten.foertsch@gmx.net>) |
| Ответы |
Re: Is this a planner bug?
|
| Список | pgsql-general |
Hello
what is your effective_cache_size in postgresql.conf?
What is random_page_cost and seq_page_cost?
Regards
Pavel
Pavel
2014-04-22 14:10 GMT+02:00 Torsten Förtsch <torsten.foertsch@gmx.net>:
Hi,
I got this plan:
Limit (cost=0.00..1.12 rows=1 width=0)
-> Seq Scan on fmb (cost=0.00..6964734.35 rows=6237993 width=0)
Filter: ...
The table has ~80,000,000 rows. So, the filter, according to the plan,
filters out >90% of the rows. Although the cost for the first row to
come out of the seqscan might be 0, the cost for the first row to pass
the filter and, hence, to hit the limit node is probably higher.
Thanks,
Torsten
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
В списке pgsql-general по дате отправления: