70ffc30e12
match_clause_to_partition_key() tells whether a comparison value can
be evaluated during executor-startup pruning by checking that it has
no Vars, no volatile functions and no PARAM_EXEC Params. A SubPlan
normally fails the last test, since the testexpr of an ANY/ALL SubPlan
references the subplan's output Params. But if the left-hand side is
a NULL constant, the strict comparison operator in the testexpr is
const-folded to a NULL Const, and an uncorrelated SubPlan has no
parParam or args either, so nothing is left for pull_exec_paramids()
to find. The expression then reaches initial_pruning_steps, where
ExecDoInitialPruning() must evaluate it before any PlanState exists,
and we fail with "SubPlan found with no parent plan".
To fix, don't allow such an expression to be used for startup-time
pruning. It's still fine for per-scan pruning, which has a PlanState
to evaluate it with. Expressions containing exec Params are
unaffected.
This has been broken since d47cbf474, which moved initial pruning out
of ExecInitNode(); before that, pruning always had the parent node's
PlanState available. Back-patch to v18.
Author: Richard Guo <guofenglinux@gmail.com>
Reviewed-by: Amit Langote <amitlangote09@gmail.com>
Discussion: https://postgr.es/m/CAMbWs48nYDu7joYeyMKYdX8kHoL_ASEax2fqZH6L+HHqO2nkXA@mail.gmail.com
Backpatch-through: 18
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/18/. In particular, information about building PostgreSQL from the source code can be found at https://www.postgresql.org/docs/18/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/.