eec0040c4b
This expands the NOT ENFORCED constraint flag, previously only supported for CHECK constraints (commit ca87c415e2f), to foreign key constraints. Normally, when a foreign key constraint is created on a table, action and check triggers are added to maintain data integrity. With this patch, if a constraint is marked as NOT ENFORCED, integrity checks are no longer required, making these triggers unnecessary. Consequently, when creating a NOT ENFORCED foreign key constraint, triggers will not be created, and the constraint will be marked as NOT VALID. Similarly, if an existing foreign key constraint is changed to NOT ENFORCED, the associated triggers will be dropped, and the constraint will also be marked as NOT VALID. Conversely, if a NOT ENFORCED foreign key constraint is changed to ENFORCED, the necessary triggers will be created, and the will be changed to VALID by performing necessary validation. Since not-enforced foreign key constraints have no triggers, the shortcut used for example in psql and pg_dump to skip looking for foreign keys if the relation is known not to have triggers no longer applies. (It already didn't work for partitioned tables.) Author: Amul Sul <sulamul@gmail.com> Reviewed-by: Joel Jacobson <joel@compiler.org> Reviewed-by: Andrew Dunstan <andrew@dunslane.net> Reviewed-by: Peter Eisentraut <peter@eisentraut.org> Reviewed-by: jian he <jian.universality@gmail.com> Reviewed-by: Alvaro Herrera <alvherre@alvh.no-ip.org> Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Isaac Morland <isaac.morland@gmail.com> Reviewed-by: Alexandra Wang <alexandra.wang.oss@gmail.com> Tested-by: Triveni N <triveni.n@enterprisedb.com> Discussion: https://www.postgresql.org/message-id/flat/CAAJ_b962c5AcYW9KUt_R_ER5qs3fUGbe4az-SP-vuwPS-w-AGA@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/.