Re: Slow dump with pg_dump/pg_restore ? How to improve ? - Mailing list pgsql-general

From Soeren Gerlach
Subject Re: Slow dump with pg_dump/pg_restore ? How to improve ?
Date
Msg-id 200407012308.19036.soeren@all-about-shift.com
Whole thread Raw
In response to Re: Slow dump with pg_dump/pg_restore ? How to improve ?  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-general
> 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
>
> Really!?  Hmm, that seems fairly backwards ... thinks ...
>
> In the -Fc case this makes some amount of sense because pg_dump runs
> gzip-style compression on the data (which is why the output file is
> so much smaller).  But for plain text dump, pg_dump should be just
> pushing the data straight through to stdout; it really ought not take
> much CPU as far as I can see.  There may be some simple performance
> glitch involved there.  Are you interested in recompiling with -pg
> and getting a gprof profile of pg_dump?

Yes I'am but I'm a little short on time ,-)) In fact I'm glad to d'l a
ready-to-run archive for Debian Woody. In two weeks I'll have some time to
check this issue with my own compiled versions, until then I'm just
interested ,-))
Today I upgraded to 7.4.3 from 7.4.1 but this did not change anything real.
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


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