Re: [real] Re: Slow dump with pg_dump/pg_restore ? How - Mailing list pgsql-general

From Don Isgitt
Subject Re: [real] Re: Slow dump with pg_dump/pg_restore ? How
Date
Msg-id 40E57B4C.9010500@soundenergy.com
Whole thread Raw
In response to Slow dump with pg_dump/pg_restore ? How to improve ?  (Soeren Gerlach <soeren@all-about-shift.com>)
List pgsql-general

Soeren Gerlach wrote:

>>Soeren Gerlach <soeren@all-about-shift.com> writes:
>>
>>
>>> * pg_dump takes 2/3 of the [single] CPU, postmaster the other 1/3 for
>>>both dumps
>>>
>Do you have numbers in respect to speed (rows per second) for comparison
>available. I.e. dump on a single CPU machine which quite fast drives?
>
>
>Regards,
>Soeren
>
>
>
>
Hi Soeren,

I just used pg_dump on my database with your settings to give you a
reference point; however, my machine is a quad-Xeon, otherwise
comparable to yours. (2G ram, 15K SCSI) Top showed nominal CPU usage of
~20-25% during the run, so that agrees with your high cpu utilization.
But, the dump took 140 secs (elapsed time) for a 2.5GB (on disk) db. The
.dmp file was 650MB, and total rows was ~3M. So, that makes ~20000
rows/sec, which certainly suggests something is amiss with your hardware
or software or configuration or ...

Don

p.s. I am running PgSQL 7.4 on Red Hat 3.2.3 (Linux kernel 2.4.21-9 SMP)



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