72bd38cc99
Replace (expr op C1) OR (expr op C2) ... with expr op ANY(ARRAY[C1, C2, ...]) on the preliminary stage of optimization when we are still working with the expression tree. Here Cn is a n-th constant expression, 'expr' is non-constant expression, 'op' is an operator which returns boolean result and has a commuter (for the case of reverse order of constant and non-constant parts of the expression, like 'Cn op expr'). Sometimes it can lead to not optimal plan. This is why there is a or_to_any_transform_limit GUC. It specifies a threshold value of length of arguments in an OR expression that triggers the OR-to-ANY transformation. Generally, more groupable OR arguments mean that transformation will be more likely to win than to lose. Discussion: https://postgr.es/m/567ED6CA.2040504%40sigaev.ru Author: Alena Rybakina <lena.ribackina@yandex.ru> Author: Andrey Lepikhov <a.lepikhov@postgrespro.ru> Reviewed-by: Peter Geoghegan <pg@bowt.ie> Reviewed-by: Ranier Vilela <ranier.vf@gmail.com> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Reviewed-by: Jian He <jian.universality@gmail.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/.