
When testing buffer pool logic, it is useful to be able to evict arbitrary blocks. This function can be used in SQL queries over the pg_buffercache view to set up a wide range of buffer pool states. Of course, buffer mappings might change concurrently so you might evict a block other than the one you had in mind, and another session might bring it back in at any time. That's OK for the intended purpose of setting up developer testing scenarios, and more complicated interlocking schemes to give stronger guararantees about that would likely be less flexible for actual testing work anyway. Superuser-only. Author: Palak Chaturvedi <chaturvedipalak1911@gmail.com> Author: Thomas Munro <thomas.munro@gmail.com> (docs, small tweaks) Reviewed-by: Nitin Jadhav <nitinjadhavpostgres@gmail.com> Reviewed-by: Andres Freund <andres@anarazel.de> Reviewed-by: Cary Huang <cary.huang@highgo.ca> Reviewed-by: Cédric Villemain <cedric.villemain+pgsql@abcsql.com> Reviewed-by: Jim Nasby <jim.nasby@gmail.com> Reviewed-by: Maxim Orlov <orlovmg@gmail.com> Reviewed-by: Thomas Munro <thomas.munro@gmail.com> Reviewed-by: Melanie Plageman <melanieplageman@gmail.com> Discussion: https://postgr.es/m/CALfch19pW48ZwWzUoRSpsaV9hqt0UPyaBPC4bOZ4W+c7FF566A@mail.gmail.com
The PostgreSQL contrib tree --------------------------- This subtree contains porting tools, analysis utilities, and plug-in features that are not part of the core PostgreSQL system, mainly because they address a limited audience or are too experimental to be part of the main source tree. This does not preclude their usefulness. User documentation for each module appears in the main SGML documentation. When building from the source distribution, these modules are not built automatically, unless you build the "world" target. You can also build and install them all by running "make all" and "make install" in this directory; or to build and install just one selected module, do the same in that module's subdirectory. Some directories supply new user-defined functions, operators, or types. To make use of one of these modules, after you have installed the code you need to register the new SQL objects in the database system by executing a CREATE EXTENSION command. In a fresh database, you can simply do CREATE EXTENSION module_name; See the PostgreSQL documentation for more information about this procedure.