PG_LANGUAGE

true: user-defined language.
false: internal language, for example, SQL.

PG_LANGUAGE registers programming languages. You can use them and APIs to write functions or stored procedures.

**Table 1** PG_LANGUAGE columns
Name	Type	Reference	Description
oid	oid	-	Row identifier (hidden attribute, which must be specified).
lanname	name	-	Language name.
lanowner	oid	oid in PG_AUTHID	Owner of the language.
lanispl	boolean	-	true: user-defined language. false: internal language, for example, SQL. Currently, gs_dump still uses this column to determine which languages need to be dumped, but this might be replaced by a different mechanism in the future.
lanpltrusted	boolean	-	true: The language is trusted, which means that it is believed not to grant access to anything outside the normal SQL execution environment. false: The language is untrusted. Only the initial user can create functions in untrusted languages.
lanplcallfoid	oid	oid in PG_PROC	For non-internal languages, this column references the language handler, which is a special function responsible for executing all functions that are written in the particular language.
laninline	oid	oid in PG_PROC	This column references a function responsible for executing "inline" anonymous code blocks (DO blocks). The value is 0 if inline blocks are not supported.
lanvalidator	oid	oid in PG_PROC	This column references a language validator function responsible for checking the syntax and validity of new functions when they are created. The value is 0 if no validator is provided.
lanacl	aclitem[]	-	Access permission.