317c117d6d
Constraint expressions and statistics expressions loaded from the system catalogs need to be run through const-simplification, because the planner will be comparing them to similarly-processed qual clauses. Without this step, the planner may fail to detect valid matches. Currently, NullTest clauses in these expressions may not be reduced correctly during const-simplification. This happens because their Var nodes do not yet have the correct varno when eval_const_expressions is applied. Since eval_const_expressions relies on varno to reduce NullTest quals, incorrect varno can cause problems. Additionally, for statistics expressions, eval_const_expressions is called with root set to NULL, which also inhibits NullTest reduction. This patch fixes the issue by ensuring that Vars are updated to have the correct varno before const-simplification, and that a valid root is passed to eval_const_expressions when needed. Author: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/19007-4cc6e252ed8aa54a@postgresql.org
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/.