PL/pgSQL

PL/pgSQL (Procedural Language/PostgreSQL Structured Query Language) is a procedural language supported by the PostgreSQL RDBMS. It closely resembles Oracle's PL/SQL language.

PL/pgSQL, as a fully featured programming language, allows much more procedural control than SQL, including the ability to use loops and other control structures. Functions created in the PL/pgSQL language can be called from an SQL statement, or as the action that a trigger performs.

PL/pgSQL was created to be able to perform more complex operations and computations than SQL, while being easy to use, and is able to be defined as trusted by the server.

PL/pgSQL is the only "PL" language installed by default for PostgreSQL, but many others are available, including PL/Java, PL/Perl, plPHP, PL/Python, PL/R, PL/Ruby, PL/sh, and PL/Tcl.