8e72239e9d
expression_returns_set() used to short-circuit its recursion upon seeing certain node types, such as DistinctExpr, that it knew the executor did not support set-valued arguments for. That was never inherent, though, just a reflection of laziness in execQual.c. With the new implementation of SRFs there is no reason to think that any scalar-valued expression node could not have a set-valued subexpression, except for AggRefs and WindowFuncs where we know there is a parser check rejecting it. And indeed, the shortcut causes unexpected failures for cases such as a SRF underneath DistinctExpr, because the planner stops looking for SRFs too soon. Discussion: https://postgr.es/m/5259.1497044025@sss.pgh.pa.us
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. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.