
Vacuum code run both by autovacuum workers and a backend doing VACUUM/ANALYZE previously inspected VacuumCostLimit and VacuumCostDelay, which are the global variables backing the GUCs vacuum_cost_limit and vacuum_cost_delay. Autovacuum workers needed to override these variables with their own values, derived from autovacuum_vacuum_cost_limit and autovacuum_vacuum_cost_delay and worker cost limit balancing logic. This led to confusing code which, in some cases, both derived and set a new value of VacuumCostLimit from VacuumCostLimit. In preparation for refreshing these GUC values more often, introduce new, independent global variables and add a function to update them using the GUCs and existing logic. Per suggestion by Kyotaro Horiguchi Author: Melanie Plageman <melanieplageman@gmail.com> Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com> Reviewed-by: Daniel Gustafsson <daniel@yesql.se> Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com> Reviewed-by: Robert Haas <robertmhaas@gmail.com> Discussion: https://www.postgresql.org/message-id/flat/CAAKRu_ZngzqnEODc7LmS1NH04Kt6Y9huSjz5pp7%2BDXhrjDA0gw%40mail.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. 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/.
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