This request allows a support function to replace a function call appearing in FROM (typically a set-returning function) with an equivalent SELECT subquery. The subquery will then be subject to the planner's usual optimizations, potentially allowing a much better plan to be generated. While the planner has long done this automatically for simple SQL-language functions, it's now possible for extensions to do it for functions outside that group. Notably, this could be useful for functions that are presently implemented in PL/pgSQL and work by generating and then EXECUTE'ing a SQL query. Author: Paul A Jungwirth <pj@illuminatedcomputing.com> Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/09de6afa-c33d-4d94-a5cb-afc6cea0d2bb@illuminatedcomputing.com
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
Copyright and license information can be found in the file COPYRIGHT.
General documentation about this version of PostgreSQL can be found at https://www.postgresql.org/docs/devel/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/devel/installation.html.
The latest version of this software, and related software, may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.