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Background workers gain a new flag, called BGWORKER_INTERRUPTIBLE, that offers the possibility to terminate the workers when these are connected to a database that is involved in one of the following commands: ALTER DATABASE RENAME TO ALTER DATABASE SET TABLESPACE CREATE DATABASE DROP DATABASE This is useful to give background workers the same behavior as backends and autovacuum workers, which are stopped when these commands are executed. The default behavior, that exists since 9.3, is still to never terminate bgworkers connected to the database involved in any of these commands. The new flag has to be set to terminate the workers. A couple of tests are added to worker_spi to track the commands that impact the termination of the workers. There is a test case for a non-interruptible worker, additionally, that relies on an injection point to make the wait time in CountOtherDBBackends() reduced from 5s to 0.3s for faster test runs. The tests rely on the contents of the server logs to check if a worker has been started or terminated: - LOG generated by worker_spi_main() at startup, once connection to database is done. - FATAL in bgworker_die() when terminated. A couple of tests run in the CI have showed that this method is stable enough. The safe_psql() calls that scan pg_stat_activity could be replaced with some poll_query_until() for more stability, if the current method proves to be an issue in the buildfarm. Author: Aya Iwata <iwata.aya@fujitsu.com> Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com> Reviewed-by: Chao Li <li.evan.chao@gmail.com> Reviewed-by: Ryo Matsumura <matsumura.ryo@fujitsu.com> Reviewed-by: Michael Paquier <michael@paquier.xyz> Reviewed-by: Peter Smith <smithpb2250@gmail.com> Discussion: https://postgr.es/m/OS7PR01MB11964335F36BE41021B62EAE8EAE4A@OS7PR01MB11964.jpnprd01.prod.outlook.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/.