Previously, transaction aborts were detected concurrently only during system catalog scans while replaying a transaction in streaming mode. This commit adds an additional CLOG lookup to check the transaction status, allowing the logical decoding to skip changes also when it doesn't touch system catalogs, if the transaction is already aborted. This optimization enhances logical decoding performance, especially for large transactions that have already been rolled back, as it avoids unnecessary disk or network I/O. To avoid potential slowdowns caused by frequent CLOG lookups for small transactions (most of which commit), the CLOG lookup is performed only for large transactions before eviction. The performance benchmark results showed there is not noticeable performance regression due to CLOG lookups. Reviewed-by: Amit Kapila, Peter Smith, Vignesh C, Ajin Cherian Reviewed-by: Dilip Kumar, Andres Freund Discussion: https://postgr.es/m/CAD21AoDht9Pz_DFv_R2LqBTBbO4eGrpa9Vojmt5z5sEx3XwD7A@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/.