Re: Cursor support in pl/pg - Mailing list pgsql-hackers

From Ian Lance Taylor
Subject Re: Cursor support in pl/pg
Date
Msg-id siitjscg9u.fsf@daffy.airs.com
Whole thread Raw
In response to Re: Cursor support in pl/pg  (Jan Wieck <JanWieck@Yahoo.com>)
Responses Re: Cursor support in pl/pg  (Jan Wieck <JanWieck@Yahoo.com>)
List pgsql-hackers
Jan Wieck <JanWieck@Yahoo.com> writes:

>     IIRC  the  patch  only  provides  the  syntax  for  CURSOR to
>     PL/pgSQL. Not real cursor support on the SPI level.  So  it's
>     still the same as before, the backend will try to suck up the
>     entire resultset into the SPI tuple table (that's memory) and
>     die if it's huge enough.
> 
>     What  we  really need is an improvement to the SPI manager to
>     support cursor (or cursor  like  behaviour  through  repeated
>     executor calls).

Agreed, but as I may have said before, 1) the problem you describe
already exists in PL/pgSQL when using the FOR x IN SELECT statement,
2) the PL/pgSQL cursor patch is useful without the improvement to the
SPI layer, 3) I would argue that the PL/pgSQL cursor patch is still
needed after the SPI layer is improved.

So I do not think that is a valid argument against installing the
PL/pgSQL cursor patch.

Ian

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