This appendix and the next one contain information regarding the modules that can be found in the contrib directory of the LightDB distribution. These include porting tools, analysis utilities, and plug-in features that are not part of the core LightDB 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.

This appendix covers extensions and other server plug-in modules found in contrib. Appendix G covers utility programs.

If you are using a pre-packaged version of LightDB, these modules are typically made available as a separate subpackage, such as postgresql-contrib.

Many modules 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. This is done by executing a CREATE EXTENSION command. In a fresh database, you can simply do

CREATE EXTENSION module_name;

This command registers the new SQL objects in the current database only, so you need to run it in each database that you want the module's facilities to be available in. Alternatively, run it in database template1 so that the extension will be copied into subsequently-created databases by default.

For all these modules, CREATE EXTENSION must be run by a database superuser, unless the module is considered “trusted”, in which case it can be run by any user who has CREATE privilege on the current database. Modules that are trusted are identified as such in the sections that follow. Generally, trusted modules are ones that cannot provide access to outside-the-database functionality.

Many modules allow you to install their objects in a schema of your choice. To do that, add SCHEMA schema_name to the CREATE EXTENSION command. By default, the objects will be placed in your current creation target schema, which in turn defaults to public.

Note, however, that some of these modules are not “extensions” in this sense, but are loaded into the server in some other way, for instance by way of shared_preload_libraries. See the documentation of each module for details.