c06e909c26
When creating an explicit Sort node for the outer path of a mergejoin, we need to determine the number of presorted keys of the outer path to decide whether explicit incremental sort can be applied. Currently, this is done by repeatedly calling pathkeys_count_contained_in. This patch caches the number of presorted outer pathkeys in MergePath, allowing us to save several calls to pathkeys_count_contained_in. It can be considered a complement to the changes in commit 828e94c9d. Reported-by: David Rowley <dgrowleyml@gmail.com> Author: Richard Guo <guofenglinux@gmail.com> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://postgr.es/m/CAApHDvqvBireB_w6x8BN5txdvBEHxVgZBt=rUnpf5ww5P_E_ww@mail.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/.