Re: URGENT: Performance tuning

On Thu, 2002-06-20 at 14:45, Joshua D. Drake wrote:
> Hello,
>
> Did you create an index? What is your shared buffers? Are you using
> Fsync, if so --- which one?

The default shared buffers that come with pgsql is very small. So you
need to really ramp this up. Read the article for some more tips. Also
check the techdocs.postgresql.org site for some good info.

For this purpose, you have to have indexes, yes.

I did not change my default Fsync settings, which i think mainly applies
to updates anyway.

- Ericson Smith
eric(at)did-it(dot)com
http://www.did-it.com
>
>
>
>
> Ericson Smith wrote:
>
> >http://phpbuilder.com/columns/smith20010821.php3
> >
> >On Thu, 2002-06-20 at 13:21, Peter Dimov wrote:
> >
> >
> >>Hi ,
> >>
> >>I need info about how to fine tune my postgresql.
> >>
> >>I make a little test and the results was not good for posgresql.
> >>
> >>I will to use the server in production and need this info.
> >>
> >>So, the test:
> >>
> >>first machine:
> >>
> >>Linux Mandrake 8.2 and posgresql on it.
> >>
> >>Dual Athlon MP 1,6 GHz , 1 GB RAM , IDE 7200 40 GB HDD.
> >>
> >>
> >>
> >>I create a litle table (field1 varchar(100),field2 varchar(100), field3 int) and fill
> >>
> >>200 000 x ('aaaaaaaaaaaaa1','bbbbbbbbbbbbbbb1',10);
> >>
> >>200 000 x ('aaaaaaaaaaaaa2','bbbbbbbbbbbbbbb2',20);
> >>
> >>200 000 x ('aaaaaaaaaaaaa3','bbbbbbbbbbbbbbb3',30);
> >>
> >>200 000 x ('aaaaaaaaaaaaa4','bbbbbbbbbbbbbbb4',40);
> >>
> >>200 000 x ('aaaaaaaaaaaaa5','bbbbbbbbbbbbbbb5',50);
> >>
> >>
> >>
> >>After that i make : select distinct field1 from mytable.
> >>
> >>As result I get 5 rows and it is OK, but the time is 3 min 30 sec.
> >>
> >>The processor usage is 50% - it is OK , and the system use the maximum of the first processor.
> >>
> >>The second machine:
> >>
> >>Athlon XP 1,5 GHz , 512 MB RAM , 7200 HDD 40 GB
> >>
> >>WinNT 4, Oracle 8i.
> >>
> >>I make the same test.
> >>
> >>The result come for 15 sec !!!!.
> >>
> >>Ok, I am sure : the diferent can not be so big.
> >>
> >>I do not make any special setup an postgres and on linux, anly the standart install.
> >>
> >>Any info or example will be great.
> >>
> >>Many thanks in advance.
> >>
> >>
> >>
> >>
> >>
> >>
> >>
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