Re: Re: new patch of MERGE (merge_204) & a question about duplicated ctid - Mailing list pgsql-hackers

From Marko Tiikkaja
Subject Re: Re: new patch of MERGE (merge_204) & a question about duplicated ctid
Date
Msg-id 4D1BF24B.6000306@cs.helsinki.fi
Whole thread Raw
In response to Re: Re: new patch of MERGE (merge_204) & a question about duplicated ctid  (Greg Smith <greg@2ndquadrant.com>)
Responses Re: Re: new patch of MERGE (merge_204) & a question about duplicated ctid  (Robert Haas <robertmhaas@gmail.com>)
Re: Re: new patch of MERGE (merge_204) & a question about duplicated ctid  (Greg Smith <greg@2ndquadrant.com>)
List pgsql-hackers
On 2010-12-30 4:39 AM +0200, Greg Smith wrote:
> And that got me back again to concurrent testing.
>
> Moving onto next two problems...the basic MERGE feature seems to have
> stepped backwards a bit too.  I'm now seeing these quite often:
>
> ERROR:  duplicate key value violates unique constraint
> "pgbench_accounts_pkey"
> DETAIL:  Key (aid)=(176641) already exists.
> STATEMENT:  MERGE INTO pgbench_accounts t USING (SELECT 176641,1+(176641
> / 1000000)::integer,168,'') AS s(aid,bid,balance,filler) ON s.aid=t.aid
> WHEN MATCHED THEN UPDATE SET abalance=abalance + s.balance WHEN NOT
> MATCHED THEN INSERT VALUES(s.aid,s.bid,s.balance,s.filler);
>
> On my concurrent pgbench test, which had been working before.

I have no idea why it worked in the past, but the patch was never 
designed to work for UPSERT.  This has been discussed in the past and 
some people thought that that's not a huge deal.


Regards,
Marko Tiikkaja


pgsql-hackers by date:

Previous
From: Greg Smith
Date:
Subject: Re: Re: new patch of MERGE (merge_204) & a question about duplicated ctid
Next
From: Jie Li
Date:
Subject: Re: small table left outer join big table