Re: WIP patch: add (PRE|POST)PROCESSOR options to COPY

Excerpts from Etsuro Fujita's message of jue sep 13 06:13:26 -0300 2012:
> I'd like to add the following options to the SQL COPY command and the psql \copy
> instruction:
>
>     * PREPROCESSOR: Specifies the user-supplied program for COPY IN.  The data
> from an input file is preprocessed by the program before the data is loaded into
> a postgres table.
>     * POSTPROCESSOR: Specifies the user-supplied program for COPY OUT.  The data
> from a postgres table is postprocessed by the program before the data is stored
> in an output file.

External programs?  I don't like the sound of that; there all kinds of
open questions, security concerns, and process management problems.
What if the pre- and postprocessors were functions instead?

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