Re: [HACKERS] [BUGS] Postgresql bug report - unexpected behavior of suppress_redundant_updates_trigger - Mailing list pgsql-hackers

From Dilip Kumar
Subject Re: [HACKERS] [BUGS] Postgresql bug report - unexpected behavior of suppress_redundant_updates_trigger
Date
Msg-id CAFiTN-tQat3h8qDVH1Z+KpYOL_PwCG0zYDzfbt-YnRxByfhSvw@mail.gmail.com
Whole thread Raw
Responses Re: [HACKERS] [BUGS] Postgresql bug report - unexpected behavior of suppress_redundant_updates_trigger  (Tom Lane <tgl@sss.pgh.pa.us>)
[HACKERS] Re: Postgresql bug report - unexpected behavior ofsuppress_redundant_updates_trigger  (J Chapman Flack <jflack@math.purdue.edu>)
List pgsql-hackers
On Mon, Jun 19, 2017 at 5:20 PM, Artus de benque
<artusdebenque@gmail.com> wrote:
> postgres=# UPDATE test_table SET field = 'hi' WHERE id = 1;
> UPDATE 0
> test_db=# UPDATE test_table SET field = rpad('', 2001, 'a') WHERE id = 1;
> UPDATE 1
> test_db=# UPDATE test_table SET field = rpad('', 2001, 'a') WHERE id = 1;
> UPDATE 1 <--- BUG: expected 0, as we ran the same update twice

Seems like in "suppress_redundant_updates_trigger"  we are comparing
toasted tuple with the new tuple and that is the cause of the bug.


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



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