Re: Slow performance - Mailing list pgsql-performance

From Kevin Grittner
Subject Re: Slow performance
Date
Msg-id 4E5E3E210200002500040926@gw.wicourts.gov
Whole thread Raw
In response to Slow performance  ("Kai Otto" <kotto@medis.nl>)
Responses Re: Slow performance  ("Kai Otto" <kotto@medis.nl>)
List pgsql-performance
"Kai Otto" <kotto@medis.nl> wrote:

> Time taken:
>
> 35.833 ms (i.e. roughly 35 seconds)

Which is it?  35 ms or 35 seconds?

> Number of rows:
>
> 121830
>
> Number of columns:
>
> 38

> This is extremely slow for a database server.
>
> Can anyone help me in finding the problem?

> "Seq Scan on "Frame"  (cost=0.00..9537.30 rows=121830 width=541)
> (actual time=0.047..93.318 rows=121830 loops=1)"
>
> "Total runtime: 100.686 ms"

Assuming 35 seconds for the 121 K rows, it would seem that you're
taking less than 1 ms per row on the database server, which may not
be too bad, depending on how many of them are read from disk.  The
rest of the time would seem to be in the network and the client.
That's where you need to fix something if you want it to be faster.

With only a fraction of 1% of the run time being on the database
server, any attempt to tune things there can't improve performance
by more than that fraction of a percent.

-Kevin

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