Statement handle caching...

In practice this is a question surrounding DBI, but:

if you make a query and send it to postgres, it gets
optimized. The resulting query tree, is it cached at all? Is it
accessable through a statement handle? Does postgres have a query
cache manager that caches frequently used queries so I don't have to
worry about this?

Anyway, caching optimized queries (or query trees): is this a
feature? If not, why? If so, where did I miss reading this (thought
I read every scrap of printed material that wasn't in the mailing
list, but still searched and read a fair bit of mailing list material
too)? -sc

--
Sean Chittenden