When the ON ERROR / ON EMPTY behavior is to return NULL, returning NULL directly from ExecEvalJsonExprPath() suffices. Therefore, there's no need to create separate steps to check the error/empty flag or those to evaluate the the constant NULL expression. This speeds up common cases because the default ON ERROR / ON EMPTY behavior for JSON_QUERY() and JSON_VALUE() is to return NULL. However, these steps are necessary if the RETURNING type is a domain, as constraints on the domain may need to be checked. Reported-by: Jian He <jian.universality@gmail.com> Author: Jian He <jian.universality@gmail.com> Author: Amit Langote <amitlangote09@gmail.com> Discussion: https://postgr.es/m/CACJufxEo4sUjKCYtda0_qt9tazqqKPmF1cqhW9KBOUeJFqQd2g@mail.gmail.com Backpatch-through: 17
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/.