Re: LIMIT for UPDATE and DELETE - Mailing list pgsql-hackers

From Marko Tiikkaja
Subject Re: LIMIT for UPDATE and DELETE
Date
Msg-id 5410047D.8010109@joh.to
Whole thread Raw
In response to Re: LIMIT for UPDATE and DELETE  (Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>)
Responses Re: LIMIT for UPDATE and DELETE  (Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>)
List pgsql-hackers
On 2014-09-10 04:25, Etsuro Fujita wrote:
> (2014/09/09 18:57), Heikki Linnakangas wrote:
>> What's not clear to me is whether it make sense to do 1) without 2) ? Is
>> UPDATE .. LIMIT without support for an ORDER BY useful enough? And if we
>> apply this patch now, how much of it needs to be rewritten after 2) ? If
>> the answers are "yes" and "not much", then we should review this patch
>> now, and put 2) on the TODO list. Otherwise 2) should do done first.
>
> My answers are "yes" but "completely rewritten".

Any particular reason for you to say that?  Because an UPDATE might have 
a RETURNING clause, all the updated tuples have to go through the 
ModifyTable node one at a time.  I don't see why we couldn't LIMIT there 
after implementing #2.


.marko



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