JsonConstructorExpr can produce non-NULL output with a NULL input, so it should be treated as a non-strict construct. Failing to do so can lead to incorrect query behavior. For example, in the reported case, when pulling up a subquery that is under an outer join, if the subquery's target list contains a JsonConstructorExpr that uses subquery variables and it is mistakenly treated as strict, it will be pulled up without being wrapped in a PlaceHolderVar. As a result, the expression will be evaluated at the wrong place and will not be forced to null when the outer join should do so. Back-patch to v16 where JsonConstructorExpr was introduced. Bug: #19046 Reported-by: Runyuan He <runyuan@berkeley.edu> Author: Tender Wang <tndrwang@gmail.com> Co-authored-by: Richard Guo <guofenglinux@gmail.com> Discussion: https://postgr.es/m/19046-765b6602b0a8cfdf@postgresql.org 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/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/.