Thread: Re: [QUESTIONS] How fully will subselects be implemented?

>
> First, this list is not right place to ask about 6.3 features :)
> 2nd, subselects within UPDATE are supported.

They are?  I thought he wanted to do:

    update test set x = (select y from taby)

I didn't think we supported that.  Can you confirm that?

> 3rd, there will be separate select (better say - separate re-scan of
> subquery' plan) for each parent row (I assume that you talk about
> correlated subqueries) but this will be more efficient than using
> SQL-funcs which do _initialization_, scannig, _closing_ of query' plan
> for each parent row. When using subqueries performance will be
> near the same as for performing Nestloop join.

Good.

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Bruce Momjian wrote:
>
> >
> > First, this list is not right place to ask about 6.3 features :)
> > 2nd, subselects within UPDATE are supported.
>
> They are?  I thought he wanted to do:
>
>         update test set x = (select y from taby)
>
> I didn't think we supported that.  Can you confirm that?

Oh, this is not supported, sorry.
And select a, (select b from tab2) from tab1 and so on...

Vadim