PostgreSQL is a powerful open source relational database management system. It extends the SQL language with additional features. A DBMS is not only defined by its performance and out of the box features, but also its ability to support bespoke/additional user-specific functionality. Some of these functionalities may be in the form of database constructs or [&]

https://www.percona.com/blog/2019/04/05/writing-postgresql-extensions-is-fun-c-language/