In many cases, useful modules may not have full packaging. In these cases, you may need to install the module manually. This isn't very hard, and it's a useful exercise that will help you understand what happens.
Each module will have different installation requirements. There are generally two aspects of installing a module. They are as follows:
- Building the libraries (only for modules that have libraries)
- Installing the module files in the appropriate locations
You need to follow the instructions for the specific module in order to build the libraries, if any are required. Installation will then be straightforward, and usually there will be a suitably prepared configuration file for the make utility, so that you just need to type the following command:
make install
Each file will be copied to the right directory. Remember that you normally need to be a system super user in order to install files on system directories.
Once a library file is in the directory expected by the PostgreSQL server, it will be loaded automatically as soon as requested by a function. Modules such as auto_explain do not provide any additional user-defined functions, so they won't be auto-loaded; that needs to be done manually by a super user with a LOAD statement.