11ff192b5b
We were unnecessarily acquiring AccessExclusiveLock on all child tables when "ALTER TABLE ONLY sometab ADD PRIMARY KEY" was run on their parent table, an oversight in commit 14e87ffa5c54. This caused deadlocks during pg_restore of partitioned tables. The reason to acquire the AEL was that we need to verify that child tables have the involved columns already marked as not-null; but if the parent table has an inheritable not-null constraint, then all children must necessarily be in the correct state already, so we can skip the check, which avoids acquiring the lock. Reorder the code so that it works that way. This doesn't change things in the case where the constraint doesn't exist, but that case is of lesser importance because it doesn't occur during parallel pg_restore. While at it, reword some errmsg() and add errhint() to similar cases in related but not adjacent code. Diagnosed-by: Tom Lane <tgl@sss.pgh.pa.us> Reviewed-by: Tender Wang <tndrwang@gmail.com> Discussion: https://postgr.es/m/67469c1c-38bc-7d94-918a-67033f5dd731@gmx.net Discussion: https://postgr.es/m/2045026.1743801143@sss.pgh.pa.us Discussion: https://postgr.es/m/1280408.1744650810@sss.pgh.pa.us
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/.