function callback

On Wed, Feb 15, 2006 at 03:47:54PM +0200, Igor Shevchenko wrote:

Here's a problem I'm facing:

I have a "mimetype" table with all mimetypes my app has to deal with. I'm in a
process of adding a fulltext indexing (tsearch2) into my DB and I want to
specify a per-mimetype conversion function which would convert corresponding
data into a text suitable for indexing. PostgreSQL has a "regprocedure"
datatype (an alias to OID?) which can be added as a column to my "mimetype"
table but I can't find a way to execute a function by regprocedure from
pl/pgsql. Is there any way to do it except writing my own "C" function ? Or
maybe I'd better off adding a "text" field for function name and calling it
from pl/pgsql with EXECUTE "string" ?

The easy answer is: not really. regprocedure is just a way to pretty
print the name of a function. PostgreSQL doesn't have the concept of a
function pointer. You'd probably be better off storing the name of the
function and building a string to EXECUTE.

If you're really desparate you could try making a postgres function
that uses OidFunctionCalln but that just opens the door to all sorts of
hacks...

Have a nice day,
--
Martijn van Oosterhout <kleptog@svana.org> http://svana.org/kleptog/