Owner
The owner of the language.
Note: Support from PostgreSQL 8.3 or later.
Schema of handler and Handler
Call Handler is the name of a previously registered function that will be called to execute the
procedural language functions. The call handler for a procedural language must be written in a
compiled language such as C with version 1 call convention and registered with PostgreSQL as a
function taking no arguments and returning the language_handler type, a placeholder type that is
simply used to identify the function as a call handler.
Schema of validator and Validator
Validator function is the name of a previously registered function that will be called when a new
function in the language is created, to validate the new function. If no validator function is
specified, then a new function will not be checked when it is created. The validator function must
take one argument of type oid, which will be the OID of the to-be-created function, and will
typically return void.
A validator function would typically inspect the function body for syntactical correctness, but it can also look at other properties of the function, for example if the language cannot handle certain argument types. To signal an error, the validator function should use the ereport() function. The return value of the function is ignored.
Trusted
Specifies that the call handler for the language is safe, that is, it does not
offer an unprivileged user any functionality to bypass access restrictions. If
this key word is omitted when registering the language, only users with the
PostgreSQL superuser privilege can use this language to create new functions.