065ce49a10
1349d2790 added support so that aggregate functions with an ORDER BY or DISTINCT clause could make use of presorted inputs to avoid an implicit sort within nodeAgg.c. That commit failed to consider that a FILTER clause may exist that filters rows before the aggregate function arguments are evaluated. That can be problematic if an aggregate argument contains an expression which could error out during evaluation. It's perfectly valid to want to have a FILTER clause which eliminates such values, and with the pre-sorted path added in 1349d2790, it was possible that the planner would produce a plan with a Sort node above the Aggregate to perform the sort on the aggregate's arguments long before the Aggregate node would filter out the non-matching values. Here we fix this by inspecting ORDER BY / DISTINCT aggregate functions which have a FILTER clause to see if the aggregate's arguments are anything more complex than a Var or a Const. Evaluating these isn't going to cause an error. If we find any non-Var, non-Const parameters then the planner will now opt to perform the sort in the Aggregate node for these aggregates, i.e. disable the presorted aggregate optimization. An alternative fix would have been to completely disallow the presorted optimization for Aggrefs with any FILTER clause, but that wasn't done as that could cause large performance regressions for queries that see significant gains from 1349d2790 due to presorted results coming in from an Index Scan. Backpatch to 16, where 1349d2790 was introduced Author: David Rowley <dgrowleyml@gmail.com> Reported-by: Kaimeh <kkaimeh@gmail.com> Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us> Discussion: https://postgr.es/m/CAK-%2BJz9J%3DQ06-M7cDJoPNeYbz5EZDqkjQbJnmRyQyzkbRGsYkA%40mail.gmail.com Backpatch-through: 16
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/17/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/17/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/.