06c418e163 introduced pg_wal_replay_wait() procedure allowing to wait for the particular LSN to be replayed on standby. The waiters were stored in the flat array. Even though scanning small arrays is fast, that might be a problem at scale (a lot of waiting processes). This commit replaces the flat shared memory array with the pairing heap, which holds the waiter with the least LSN at the top. This gives us O(log N) complexity for both inserting and removing waiters. Reported-by: Alvaro Herrera Discussion: https://postgr.es/m/202404030658.hhj3vfxeyhft%40alvherre.pgsql
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/.