The catalog pg_pltemplate stores "template" information for procedural languages. A template for a language allows the language to be created in a particular database by a simple CREATE LANGUAGE command, with no need to specify implementation details.

Unlike most system catalogs, pg_pltemplate is shared across all databases of a cluster: there is only one copy of pg_pltemplate per cluster, not one per database. This allows the information to be accessible in each database as it is needed.

Table 49-35. pg_pltemplate Columns

Name Type Description
tmplname name Name of the language this template is for
tmpltrusted boolean True if language is considered trusted
tmpldbacreate boolean True if language may be created by a database owner
tmplhandler text Name of call handler function
tmplinline text Name of anonymous-block handler function, or null if none
tmplvalidator text Name of validator function, or null if none
tmpllibrary text Path of shared library that implements language
tmplacl aclitem[] Access privileges for template (not actually used)

There are not currently any commands that manipulate procedural language templates; to change the built-in information, a superuser must modify the table using ordinary INSERT , DELETE , or UPDATE commands.

Note: It is likely that pg_pltemplate will be removed in some future release of PostgreSQL , in favor of keeping this knowledge about procedural languages in their respective extension installation scripts.