Re: pg_dump slower than pg_restore - Mailing list pgsql-general

From Bosco Rama
Subject Re: pg_dump slower than pg_restore
Date
Msg-id 53B6F2DA.3010407@boscorama.com
Whole thread Raw
In response to Re: pg_dump slower than pg_restore  (David Wall <d.wall@computer.org>)
Responses Re: pg_dump slower than pg_restore  (David Wall <d.wall@computer.org>)
List pgsql-general
On 07/03/14 22:51, David Wall wrote:
>
> It just seems odd that pg_dump is slower than pg_restore to me. Most
> grumblings I read about suggest that pg_restore is too slow.
>
> I have noted that the last split file segment will often appear to be
> done -- no file modifications -- while pg_dump is still running, often
> for another 20 minutes or so, and then some last bit is finally
> written.  It's as if pg_dump is calculating something at the end that is
> quite slow.  At startup, there's a delay before data is written, too,
> but it's generally 1-2 minutes at most.

Random thought:  What OS & kernel are you running?  Kernels between
3.2.x and 3.9.x were known to have IO scheduling issues.  This was
highlighted most by the kernel in Ubuntu 12.04 (precise) as shown
here:

<http://www.postgresql.org/message-id/50BF9247.2010800@optionshouse.com>

Bosco.


pgsql-general by date:

Previous
From: David Wall
Date:
Subject: Re: pg_dump slower than pg_restore
Next
From: François Beausoleil
Date:
Subject: index contains unexpected zero page at block error