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In RI_FKey_pk_upd_check_required(), we check among other things whether the old and new key are equal, so that we don't need to run cascade actions when nothing has actually changed. This was using the equality operator. But the effect of this is that if a value in the primary key is changed to one that "looks" different but compares as equal, the update is not propagated. (Examples are float -0 and 0 and case-insensitive text.) This appears to violate the SQL standard, and it also behaves inconsistently if in a multicolumn key another key is also updated that would cause the row to compare as not equal. To fix, if we are looking at the PK table in ri_KeysEqual(), then do a bytewise comparison similar to record_image_eq() instead of using the equality operators. This only makes a difference for ON UPDATE CASCADE, but for consistency we treat all changes to the PK the same. For the FK table, we continue to use the equality operators. Discussion: https://www.postgresql.org/message-id/flat/3326fc2e-bc02-d4c5-e3e5-e54da466e89a@2ndquadrant.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. PostgreSQL has many language interfaces, many of which are listed here: https://www.postgresql.org/download See the file INSTALL for instructions on how to build and install PostgreSQL. That file also lists supported operating systems and hardware platforms and contains information regarding any other software packages that are required to build or run the PostgreSQL system. Copyright and license information can be found in the file COPYRIGHT. A comprehensive documentation set is included in this distribution; it can be read as described in the installation instructions. The latest version of this software may be obtained at https://www.postgresql.org/download/. For more information look at our web site located at https://www.postgresql.org/.