d29d469bec
Incremental Sort's costs heavily depend on the estimated number of input groups with equal presorted key values. Overestimations can cause the planner to choose Incremental Sort over Sort when Sort would have been a better choice. Here, we add the planner's estimate to EXPLAIN to allow easier understanding of why Incremental Sort has been chosen. Author: Ilia Evdokimov <ilya.evdokimov@tantorlabs.com> Reviewed-by: Enrique Sánchez <enriqueesanchz@gmail.com> Reviewed-by: David Rowley <dgrowleyml@gmail.com> Reviewed-by: solai v <solai.cdac@gmail.com> Discussion: https://postgr.es/m/10682fef-3748-43f5-a932-7adcdd9bd2b8%40tantorlabs.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/.