Re: [HACKERS] UPDATE of partition key

On Fri, Feb 24, 2017 at 1:18 PM, David G. Johnston
<david.g.johnston@gmail.com> wrote:
> For my own sanity - the move update would complete successfully and break
> every ctid chain that it touches.  Any update lined up behind it in the lock
> queue would discover their target record has been deleted and would
> experience whatever behavior their isolation level dictates for such a
> situation.  So multi-partition update queries will fail to update some
> records if they happen to move between partitions even if they would
> otherwise match the query's predicate.

Right.  That's the behavior for which I am advocating, on the grounds
that it's the simplest to implement and if we all agree on something
else more complicated later, we can do it then.

> Is there any difference in behavior between this and a SQL writeable CTE
> performing the same thing via delete-returning-insert?

Not to my knowledge.

-- 
Robert Haas
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