Re: pg_dump 3 times as slow after 8.4 -> 9.5 upgrade - Mailing list pgsql-performance

From Tom Lane
Subject Re: pg_dump 3 times as slow after 8.4 -> 9.5 upgrade
Date
Msg-id 20863.1511298080@sss.pgh.pa.us
Whole thread Raw
In response to Re: pg_dump 3 times as slow after 8.4 -> 9.5 upgrade  ("Henrik Cednert (Filmlance)" <henrik.cednert@filmlance.se>)
Responses Re: pg_dump 3 times as slow after 8.4 -> 9.5 upgrade  ("Henrik Cednert (Filmlance)" <henrik.cednert@filmlance.se>)
List pgsql-performance
"Henrik Cednert (Filmlance)" <henrik.cednert@filmlance.se> writes:
> I'm not sure if I can attach screenshots here. Trying, screenshot from instruments after running for a few mins.

It looks like practically all of pg_dump's time is going into deflate(),
ie zlib.  I don't find that terribly surprising in itself, but it offers
no explanation for why you'd see a slowdown --- zlib isn't even our
code, nor has it been under active development for a long time, so
presumably 8.4 and 9.5 would have used the same version.  Perhaps you
were doing the 8.4 dump without compression enabled?
        regards, tom lane


pgsql-performance by date:

Previous
From: "Henrik Cednert (Filmlance)"
Date:
Subject: Re: pg_dump 3 times as slow after 8.4 -> 9.5 upgrade
Next
From: "Henrik Cednert (Filmlance)"
Date:
Subject: Re: pg_dump 3 times as slow after 8.4 -> 9.5 upgrade