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fc069a3a6319 implements Self-Join Elimination (SJE), which can remove base relations when appropriate. However, regressions tests for SJE only cover the case when placeholder variables (PHVs) are evaluated and needed only in a single base rel. If this baserel is removed due to SJE, its clauses, including PHVs, will be transferred to the keeping relation. Removing these PHVs may trigger an error on plan creation -- thanks to the b3ff6c742f6c for detecting that. This commit skips removal of PHVs during SJE. This might also happen that we skip the removal of some PHVs that could be removed. However, the overhead of extra PHVs is small compared to the complexity of analysis needed to remove them. Reported-by: Alexander Lakhin <exclusion@gmail.com> Author: Alena Rybakina <a.rybakina@postgrespro.ru> Author: Andrei Lepikhov <lepihov@gmail.com> Reviewed-by: Alexander Korotkov <aekorotkov@gmail.com> Reviewed-by: Richard Guo <guofenglinux@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/.