Re: What's a lot of connections? - Mailing list pgsql-performance

From Tom Lane
Subject Re: What's a lot of connections?
Date
Msg-id 11126.1121436976@sss.pgh.pa.us
Whole thread Raw
In response to Re: What's a lot of connections?  ("Jeffrey W. Baker" <jwbaker@acm.org>)
List pgsql-performance
"Jeffrey W. Baker" <jwbaker@acm.org> writes:
> On Fri, 2005-07-15 at 00:00 -0700, Karim Nassar wrote:
>> I am working on a system that uses postgresql 7.4.2 (can't change that
>> until 8.1 goes stable). Just figured out that there are about 285,000
>> connections created over about 11 hours every day. That averages out to
>> about 7.2 connections per second.
>>
>> Is that a lot? I've never seen that many.

> I see about 8 million connections per full day.  Connecting to postgres
> is cheap.

It's not *that* cheap.  I think you'd get materially better performance
if you managed to pool your connections a bit.  By the time a backend
has started, initialized itself, joined a database, and populated its
internal caches with enough catalog entries to get useful work done,
you've got a fair number of cycles invested in it.  Dropping the backend
after only one or two queries is just not going to be efficient.

            regards, tom lane

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