Re: Beginner optimization questions, esp. regarding Tsearch2 - Mailing list pgsql-performance

From Carl Youngblood
Subject Re: Beginner optimization questions, esp. regarding Tsearch2
Date
Msg-id e5ed7b690608160834h2560dceg326f6db7be668e87@mail.gmail.com
Whole thread Raw
In response to Re: Beginner optimization questions, esp. regarding Tsearch2  ("Jim C. Nasby" <jnasby@pervasive.com>)
Responses Re: Beginner optimization questions, esp. regarding Tsearch2  ("Jim C. Nasby" <jnasby@pervasive.com>)
List pgsql-performance
The relevant portion of my sysctl.conf file looks like this:

kernel.shmall = 2097152
kernel.shmmax = 2147483648
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 65536

I understood it was a good idea to set shmmax to half of available
memory (2GB in this case).  I assume that I need to set shared_buffers
slightly lower than 2GB for postgresql to start successfully.

Carl

On 8/15/06, Jim C. Nasby <jnasby@pervasive.com> wrote:
> On Tue, Aug 15, 2006 at 12:47:54PM -0600, Carl Youngblood wrote:
> > I tried setting it to 2GB and postgres wouldn't start.  Didn't
> > investigate in much greater detail as to why it wouldn't start, but
> > after switching it back to 1GB it started fine.
>
> Most likely because you didn't set the kernel's shared memory settings
> high enough.

pgsql-performance by date:

Previous
From: "Dave Dutcher"
Date:
Subject: Re: Big diference in response time (query plan question)
Next
From: "Peter Hardman"
Date:
Subject: PostgreSQL runs a query much slower than BDE and MySQL