Обсуждение: Increasing Shared Memory size, in order to increase shared buffer size

I want to increase the buffer size on my postgresql installation, in
order to improve the performance.

Now, when I execute top, on my FreeBSD system, the memory part shows:

Mem: 26M Active, 1062M Inact, 146M Wired, 199M Buf, 776M Free
Swap: 4080M Total, 8K Used, 4080M Free

The size of the database in PGDATA/base is 415 MB. I want to increase
the shared buffer size so that I could avoid swap pagein activities.

What should I increase the shared memory size of FreeBSD to be?  What
would be a good value for the shared buffer size?

Thanks in advance.

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> I want to increase the buffer size on my postgresql installation, in
> order to improve the performance.
>
> Now, when I execute top, on my FreeBSD system, the memory part shows:
>
> Mem: 26M Active, 1062M Inact, 146M Wired, 199M Buf, 776M Free
> Swap: 4080M Total, 8K Used, 4080M Free
>
> The size of the database in PGDATA/base is 415 MB. I want to increase
> the shared buffer size so that I could avoid swap pagein activities.
>
> What should I increase the shared memory size of FreeBSD to be?

Have you recompiled your kernel with the values suggested in
/usr/local/pgsql/post-install-notes ?

> What would be a good value for the shared buffer size?

See the archives, there's plenty of discussion on the topic.

Be sure that you're not trying to prevent paging of inactive pages to
disk: that isn't harmful and helps performance.  FreeBSD is relatively
aggressive about paging inactive pages and isn't harmful as it frees up
additional ram for other processes/PostgreSQL.  -sc

--
Sean Chittenden