87a350e1f2
Before this commit, when multixid wraparound happens, MultiXactState->nextMXact goes to 0, which is invalid. All the readers need to deal with that possibility and skip over the 0. That's error-prone and we've missed it a few times in the past. This commit changes the responsibility so that all the writers of MultiXactState->nextMXact skip over the zero already, and readers can trust that it's never 0. We were already doing that for MultiXactState->oldestMultiXactId; none of its writers would set it to 0. ReadMultiXactIdRange() was nevertheless checking for that possibility. For clarity, remove that check. Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Maxim Orlov <orlovmg@gmail.com> Discussion: https://www.postgresql.org/message-id/3624730d-6dae-42bf-9458-76c4c965fb27@iki.fi
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/.