Re: FETCH in subqueries or CTEs - Mailing list pgsql-general

From Pavel Stehule
Subject Re: FETCH in subqueries or CTEs
Date
Msg-id CAFj8pRBdh9DbPHkpwiifXMc+pxo0XYjTdhcJ8K-bPO4eUV7A+g@mail.gmail.com
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In response to Re: FETCH in subqueries or CTEs  (Craig Ringer <ringerc@ringerc.id.au>)
List pgsql-general
2012/8/24 Craig Ringer <ringerc@ringerc.id.au>:
> On 08/24/2012 12:34 PM, Pavel Stehule wrote:
>
>> you can't mix planned and unplanned statements together - think about
>> stored plans every time
>
>
> Thanks Pavel and Jeff.
>
> I can't say I fully understand the arguments, but I'll take it that
> accepting cursors in CTEs or subqueries wouldn't make sense. I guess the
> main issue really is that you'd have to materialize them anyway to avoid
> issues with multiple scans, so there's little point having a cursor.
>
> I didn't find a reasonable way to simply fetch a cursor into a (possibly
> temporary) table, like:
>
> INSERT INTO sometable FETCH ALL FROM somecursor;

it should be implemented as function - like materialize_cursor(cursor, table)

I would to see full support of stored procedures (with multirecordsets) rather.

Regards

Pavel

>
> ... which could be handy with PL/PgSQL functions that return multiple
> refcursors. It only seems to be possible via a PL/PgSQL wrapper that loops
> over the cursor and returns a rowset.
>
> --
> Craig Ringer


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