Writing functions in PostgreSQL is an extremely powerful tool. PostgreSQL functions provide the ability to add functionality to the database core, in order to increase performance, security, and maintainability.

These functions can be written in just about any language that is available to the open source community and several that are proprietary. If the language that you want to write them in is not available, it can be made available quickly and easily through a very robust and complete compatibility layer. In this chapter, we only looked at PL/pgSQL functions.

In the next chapter, we will focus more on PL/pgSQL functions, and take a look at the different ways in which data can be returned using OUT parameters and return values.