Re: Question about postmaster's CPU usage - Mailing list pgsql-performance

From Merlin Moncure
Subject Re: Question about postmaster's CPU usage
Date
Msg-id CAHyXU0ynObZ78d5Wjm+FSbqr7pB4k_eBBXubiSf7fOp2t69uwQ@mail.gmail.com
Whole thread Raw
In response to Re: Question about postmaster's CPU usage  (Kelphet Xiong <kelphet@gmail.com>)
List pgsql-performance
On Sat, Mar 30, 2013 at 11:00 PM, Kelphet Xiong <kelphet@gmail.com> wrote:
> I guess it is because postgres only uses a single thread to read
> the data or “pushing the data around in RAM” according to Kevin’s statement.
> Then my question is actually why postgres can not use the remaining
> 93.4%CPU.

postgres can use an arbitrary amount of threads to read data, but only
one per database connection.

> Btw, I also tried the command suggested by Ants Aasma, but got an error:
>
> explain (analyze on, timing off) select * from inventory;
> ERROR:  syntax error at or near "analyze"
>
> LINE 1: explain (analyze on, timing off) select * from inventory;
>
>                  ^

Ability to manipulate timing was added in 9.2.

merlin


pgsql-performance by date:

Previous
From: Tom Lane
Date:
Subject: Re: query plan estimate
Next
From: Armand du Plessis
Date:
Subject: Problems with pg_locks explosion