We're learning how do functions work and we found out this language (?) on the selection, we didn't find any documentation, neither on pgadmin's official website... Any help is appreciated!

CodePudding user response：

Don't search the pgadmin4 documentation, but look at the SQL tab of the dialog to see the generated SQL commands. Then refer to the official postgres documentation on CREATE FUNCTION, it mentions internal as one of the possible languages.

Admittedly, that still doesn't tell you a lot, but when searching the docs for "internal function" you'll find chapter 38 about extending the PostgreSQL SQL query language. In particular, it talks about internal functions:

Internal functions are functions written in C that have been statically linked into the PostgreSQL server. The “body” of the function definition specifies the C-language name of the function, which need not be the same as the name being declared for SQL use.