Re: [HACKERS] PL/Perl list value return causes segfault

David Fetter wrote:

>*** 716,724 ****
>
> <listitem>
> <para>
>! In the current implementation, if you are fetching or returning
>! very large data sets, you should be aware that these will all go
>! into memory.
> </para>
> </listitem>
> </itemizedlist>
>--- 766,776 ----
>
> <listitem>
> <para>
>! If you are fetching or returning very large data sets using
>! <literal>spi_exec_query</literal>, you should be aware that
>! these will all go into memory. You can avoid this by using
>! <literal>spi_query</literal>/<literal>spi_fetchrow</literal> as
>! illustrated earlier.
> </para>
> </listitem>
> </itemizedlist>
>
>
>
>

You have rolled 2 problems into one - spi_query+spi_fetchrow does not
address the issue of returning large data sets.

Suggest instead:

<para>

If you are fetching very large data sets using
<literal>spi_exec_query</literal>, you should be aware that
these will all go into memory. You can avoid this by using
<literal>spi_query</literal> and <literal>spi_fetchrow</literal>
as illustrated earlier.
</para>
<para>
A similar problem occurs if a set-returning function passes
a large set of rows back to postgres via
<literal>return</literal>. You can avoid this
problem too by instead using <literal>return_next</literal> for
each row returned, as shown previously.
</para>

cheers

andrew