Re: Slow copy with little CPU/disk usage - Mailing list pgsql-performance

From Tom Lane
Subject Re: Slow copy with little CPU/disk usage
Date
Msg-id 19670.1113966354@sss.pgh.pa.us
Whole thread Raw
In response to Slow copy with little CPU/disk usage  ("Jim C. Nasby" <decibel@decibel.org>)
Responses Re: Slow copy with little CPU/disk usage  (Mischa Sandberg <mischa.sandberg@telus.net>)
List pgsql-performance
"Jim C. Nasby" <decibel@decibel.org> writes:
> A friend of mine has an application where he's copying in 4000 rows at a
> time into a table that has about 4M rows. Each row is 40-50 bytes. This
> is taking 25 seconds on a dual PIII-1GHz with 1G of RAM and a 2 disk
> SATA mirror, running FBSD 4.10-stable. There's one index on the table.

If there's no hidden costs such as foreign key checks, that does seem
pretty dang slow.

> What's really odd is that neither the CPU or the disk are being
> hammered. The box appears to be pretty idle; the postgresql proces is
> using 4-5% CPU.

It's very hard to believe that *neither* disk nor CPU is maxed.
Can we see a reproducible test case, please?

            regards, tom lane

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