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In 61444bfb we started to allow HAVING clauses to be fully pushed down into WHERE, even when grouping sets are in use. That turns out not to work correctly, because grouping sets can "produce" NULLs, meaning that filtering in WHERE and HAVING can have different results, even when no aggregates or volatile functions are involved. Instead only allow pushdown of empty grouping sets. It'd be nice to do better, but the exact mechanics of deciding which cases are safe are still being debated. It's important to give correct results till we find a good solution, and such a solution might not be appropriate for backpatching anyway. Bug: #13863 Reported-By: 'wrb' Diagnosed-By: Dean Rasheed Author: Andrew Gierth Reviewed-By: Dean Rasheed and Andres Freund Discussion: 20160113183558.12989.56904@wrigleys.postgresql.org Backpatch: 9.5, where grouping sets were introduced
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: http://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 http://www.postgresql.org/download/. For more information look at our web site located at http://www.postgresql.org/.