Re: [HACKERS] two records with same oid, freak accident?

Massimo Dal Zotto <dz@cs.unitn.it>

From: Massimo Dal Zotto <dz@cs.unitn.it>
To: hackers@postgreSQL.org (PostgreSQL Hackers)
Date: 1998-07-18T15:32:32Z
Lists: pgsql-hackers
> 
> 
> in some sort of freak accident, we've ended up with a duplicated
> record.  all info, including the oid was duplicated.
> 
> it was during an update, two people ran a command at the same time.
> 
> user 1: BEGIN
> user 1: NOTIFY
> user 1: UPDATE
> user 2: BEGIN
> user 2: NOTIFY
> user 1: END
> user 2: UPDATE
> user 2: END
> 
> same command, so the queries are the same.  the record duplicated was
> the one being updated.  i'll try to reproduce it.
> 
> also, I had a unique index on the table, but that didn't seem to make
> any difference.
> 
> any ideas on how to delete one without deleting both?
> 

I have the same problem with pg_listeners. Sometimes I find duplicate records
with same oid in the table inserted by concurrent transactions. I suspect 
that the problem is caused by the notify but I'm not sure. Could you post
some test commnds to reproduce the problem ?

-- 
Massimo Dal Zotto

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