Writing a join selectivity function

Angela Maduko <ifymaduko@gmail.com> writes:

I am trying to write a join selectivity function for a user defined
operator. The available documentation does not exactly specify how to
go about this. Can anyone shed more light on this?

There isn't a lot of documentation, no :-(. I would suggest looking
over the existing selectivity functions (in
src/backend/utils/adt/selfuncs.c). If you have specific questions,
pghackers is probably the best place to ask them.

regards, tom lane