| lanname | name | | Name of the language (to be specified when creating a function) |
| lanispl | bool | | This is false for internal languages (such as SQL) and true for user-defined languages. Currently, pg_dump still uses this to determine which languages need to be dumped, but this may be replaced by a different mechanism sometime. |
| lanpltrusted | bool | | This is a trusted language. See under CREATE LANGUAGE what this means. If this is an internal language (lanispl is false) then this field is meaningless. |
| lanplcallfoid | oid | pg_proc.oid | For non-internal languages this references the language handler, which is a special function that is responsible for executing all functions that are written in the particular language. |
| lanvalidator | oid | pg_proc.oid | This references a language validator function that is responsible for checking the syntax and validity of new functions when they are created. See under CREATE LANGUAGE for further information about validators. |
| lanacl | aclitem[] | | Access permissions |
