Re: Concurrency bug in UPDATE of partition-key

Dilip Kumar <dilipbalaut@gmail.com>

From: Dilip Kumar <dilipbalaut@gmail.com>
To: Amit Khandekar <amitdkhan.pg@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2018-06-18T05:58:19Z
Lists: pgsql-hackers
On Mon, Jun 18, 2018 at 10:21 AM, Amit Khandekar <amitdkhan.pg@gmail.com> wrote:
> Attached is v2 version of the patch. It contains the above
> trigger-related issue fixed.
>
> The updated tuple is passed back using the existing newslot parameter
> of GetTupleForTrigger(). When ExecBRDeleteTriggers() is called using a
> new epqslot parameter, it means caller wants to skip the trigger
> execution, because the updated tuple needs to be again checked for
> constraints. I have added comments of this behaviour in the
> ExecBRDeleteTriggers() function header.
>

Thanks for the updated patch.  I have verified the BR trigger
behaviour, its working fine with the patch.

+  CREATE FUNCTION func_footrg() RETURNS TRIGGER AS $$
+  BEGIN
+     RETURN OLD;
+  END $$ LANGUAGE PLPGSQL;
+  CREATE TRIGGER footrg_ondel BEFORE DELETE ON footrg1
+   FOR EACH ROW EXECUTE PROCEDURE func_footrg();

Should we also create a test case where we can verify that some
unnecessary or duplicate triggers are not executed?  For example,  in
the above trigger function, we can maintain a count in some table (e.g
how many time delete trigger got executed) and after test over we can
verify the same.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com


Commits

  1. Allow using the updated tuple while moving it to a different partition.