Re: How can I pushdown of functions used in targetlist with FDW ?
Tom Lane <[email protected]> Wed, 08 Jan 2020 23:53:19 -0500
| Newsgroups | gmane.comp.db.postgresql.general |
|---|---|
| Message-ID | <[email protected]> |
shigeo Hirose <[email protected]> writes: > How can I pushdown of functions used in targetlist with FDW ? There is, AFAIK, no provision for that. There's not a lot of reason to consider adding it either, because there's no reason to suppose that the remote node can run such a function any faster than the local node. So the difficulty and risk of determining/assuming that f(x) on the local node is the same as f(x) on the remote node doesn't seem like it'd be repaid. You can force matters by making a foreign table that points to a view on the remote side, where the view includes the function call as an output column. It wouldn't be perfectly transparent of course; you'd have to modify the local query to refer to that column rather than calling the function explicitly. regards, tom lane