0294df2f1f
This allows MERGE commands to include WHEN NOT MATCHED BY SOURCE actions, which operate on rows that exist in the target relation, but not in the data source. These actions can execute UPDATE, DELETE, or DO NOTHING sub-commands. This is in contrast to already-supported WHEN NOT MATCHED actions, which operate on rows that exist in the data source, but not in the target relation. To make this distinction clearer, such actions may now be written as WHEN NOT MATCHED BY TARGET. Writing WHEN NOT MATCHED without specifying BY SOURCE or BY TARGET is equivalent to writing WHEN NOT MATCHED BY TARGET. Dean Rasheed, reviewed by Alvaro Herrera, Ted Yu and Vik Fearing. Discussion: https://postgr.es/m/CAEZATCWqnKGc57Y_JanUBHQXNKcXd7r=0R4NEZUVwP+syRkWbA@mail.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/.