Re: 9.5: UPDATE/DELETE .. ORDER BY .. LIMIT ..

On 2014-05-11 10:33:10 +0200, Simon Riggs wrote:
> On 11 May 2014 07:37, Amit Kapila <amit.kapila16@gmail.com> wrote:
> 
> > Tom Lane has explained these problems in a very clear manner
> > in his below mail and shared his opinion about this feature as
> > well.
> > http://www.postgresql.org/message-id/26819.1291133045@sss.pgh.pa.us
> 
> I don't have Tom's wonderfully articulate way of saying things, so
> I'll say it my way:
> 
> If you want to do this, you already can already write a query that has
> the same effect. But supporting the syntax directly to execute a
> statement with an undefinable outcome is a pretty bad idea, and worse
> than that, there's a ton of useful things that we *do* want that would
> be a much higher priority for work than this. If you support Postgres,
> prioritise, please.

I don't know. I'd find UPDATE/DELETE ORDER BY something rather
useful. It's required to avoid deadlocks in many scenarios and it's not
that obvious how to write the queries in a correct manner.
LIMIT would be a nice bonus for queues, especially if we can get SKIP
LOCKED.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services