Re: slow select in big table
| От | Abbas |
|---|---|
| Тема | Re: slow select in big table |
| Дата | |
| Msg-id | bb2cdf790904021911l7609b03bk53c802b7a82bb414@mail.gmail.com обсуждение исходный текст |
| Ответ на | slow select in big table (rafalak <rafalak@gmail.com>) |
| Список | pgsql-general |
On Fri, Apr 3, 2009 at 2:18 AM, rafalak <rafalak@gmail.com> wrote:
Is the table has indexes?Hello i have big table
80mln records, ~6GB data, 2columns (int, int)
if query
select count(col1) from tab where col2=1234;
return low records (1-10) time is good 30-40ms
but when records is >1000 time is >12s
How to increse performace ?
my postgresql.conf
shared_buffers = 810MB
temp_buffers = 128MB
work_mem = 512MB
maintenance_work_mem = 256MB
max_stack_depth = 7MB
effective_cache_size = 800MB
db 8.3.7
server, atlon dual-core 2,0Ghz, 2GB RAM, SATA
--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general
Decreasing the work_mem also increase performance.
Monitor these changes by explain the query plan.
Regards,
Abbas.
В списке pgsql-general по дате отправления: