Tom Lane wrote:
> Joe Conway may already have written something like this --- look in his
> contrib modules.
>
I did write the function, but it isn't in any of the contrib modules.
Here's a link to the thread:
http://archives.postgresql.org/pgsql-hackers/2002-12/msg00453.php
It was never committed due to dissatisfaction over the fact that table
functions cannot have columns from other FROM clause items as arguments.
Since then Peter pointed out that SQL99 specifically includes this
functionality with the keyword UNNEST, and uses a LATERAL clause to
allow referencing adjacent FROM items. Hopefully I'll find time to
pursue implementing that for 7.5.
Joe