On Wed, Oct 29, 2008 at 12:40 PM, David Fetter <david@fetter.org> wrote:
> Also, PL/Perl shouldn't be the only language to have this capability.
> How might we add similar capabilities to PL/PythonU and PL/Tcl? To
> the rest of the PLs? Would it make any sense to have it in SQL
> language functions?
Here's a vote for allowing this in plain SQL.
I use the tablefunc contrib module as a way to build a view of a
specific questionnaire's responses (using Elein's nice model here
[1]). Currently, if I then write queries against these views that
include WHERE clauses they don't perform very well as the underlying
data size grows. I was using the afore-mentioned large view that casts
everything to text, but recently I started using separate calls to the
crosstab function for each underlying table, then joining them
together based on their response ID. This seems to work much better
for more complex queries, but I think it would still be beneficial to
have access to these qualifiers so I could push down to each subquery
the list of response ID's to pull. I don't have access to sample SQL
at the moment, but if it is wanted I can try to get that this week.
David Blewett
1. http://www.varlena.com/GeneralBits/110.php