Re: Possible bug in pg_settings/pg_depend - Mailing list pgsql-hackers

From Robert Haas
Subject Re: Possible bug in pg_settings/pg_depend
Date
Msg-id AANLkTik1Yemt_P-qQCEz7jdQ=ZDq3vFME9QS5AtRnqjz@mail.gmail.com
Whole thread Raw
In response to Re: Possible bug in pg_settings/pg_depend  (Joel Jacobson <joel@gluefinance.com>)
List pgsql-hackers
On Thu, Jan 13, 2011 at 2:04 PM, Joel Jacobson <joel@gluefinance.com> wrote:
> 2011/1/13 Tom Lane <tgl@sss.pgh.pa.us>:
>> Yes, probably.  It's certainly possible to have the same linkage occur
>> with different deptypes.  We don't try hard to avoid dups because they
>> don't matter.
>
> "with different deptypes", yes, but in this case there were two
> linkages of the same deptype.
>
> Just seems a bit strange I only found one such in the entire database,
> smells like some kind of bug, but might not be, I dunno, just thought
> it was worth investigating a bit, but if you're sure about it I of
> course trust you.

Instead of trusting him, you could investigate why it happens.  A
quick test shows this eliminates both dependencies:

drop rule pg_settings_u on pg_settings;

It appears that both of the dependencies in question are from that
rule and pointing to pg_settings.name, and it looks like that rule
mentions the name column of pg_settings twice.  With a little further
experimentation you can probably tease out whether each of the two
mentions produced a separate dependency...  my guess is "yes".

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company


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