Re: Too slow "Analyze" for the table with data in Thai language - Mailing list pgsql-bugs

From Timur Luchkin
Subject Re: Too slow "Analyze" for the table with data in Thai language
Date
Msg-id emb351f641-830d-4ccd-a07a-e6e49a967605@luchkin-new
Whole thread Raw
In response to Re: Too slow "Analyze" for the table with data in Thai language  (Peter Geoghegan <pg@bowt.ie>)
List pgsql-bugs
Hello,

complete result of the perf is in the attachment.
The part with glibc looks like:

# Children      Self       Samples  Command        Shared Object
    Symbol
# ........  ........  ............  .............
.......................
....................................................
59.26%    59.25%        815883  postgres       libc-2.23.so
[.] __strcoll_l

--59.26%--__strcoll_l

p.s.
1. perf executed during 'long' ANALYZE as "perf record -a -g";
2. test server has 2 CPU cores
3. this is dedicated server without any parallel activity

--
Timur Luchkin


>On Tue, Jul 5, 2016 at 8:33 AM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>>  So ... why do you think this is a Postgres bug and not a glibc bug?
>>  We have no control over what happens inside strcoll().
>
>I'd be interested in seeing exactly where time is spent by glibc.
>Perhaps Timur can use perf to show us a profile using the default perf
>event type:
>
>https://wiki.postgresql.org/wiki/Profiling_with_perf
>
>--
>Peter Geoghegan
Attachment

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