From PostgreSQL wiki
ALTER EXTENSION -- change the definition of an extension
ALTER EXTENSION extension_name UPDATE [ TO new_version ] ALTER EXTENSION extension_name SET SCHEMA new_schema ALTER EXTENSION extension_name ADD member_object ALTER EXTENSION extension_name DROP member_object
where member_object is:
AGGREGATE agg_name (agg_type [, ...] ) | CAST (source_type AS target_type) | COLLATION object_name | CONVERSION object_name | DOMAIN object_name | FOREIGN DATA WRAPPER object_name | FOREIGN TABLE object_name | FUNCTION function_name ( [ [ argmode ] [ argname ] argtype [, ...] ] ) | OPERATOR operator_name (left_type, right_type) | OPERATOR CLASS object_name USING index_method | OPERATOR FAMILY object_name USING index_method | [ PROCEDURAL ] LANGUAGE object_name | SCHEMA object_name | SEQUENCE object_name | SERVER object_name | TABLE object_name | TEXT SEARCH CONFIGURATION object_name | TEXT SEARCH DICTIONARY object_name | TEXT SEARCH PARSER object_name | TEXT SEARCH TEMPLATE object_name | TYPE object_name | VIEW object_name
ALTER EXTENSION changes the definition of an installed extension. There are several subforms:
UPDATE This form updates the extension to a newer version. The extension must supply a suitable update script (or series of scripts) that can modify the currently-installed version into the requested version.
SET SCHEMA This form moves the extension's objects into another schema. The extension has to be relocatable for this command to succeed.
ADD member_object This form adds an existing object to the extension. This is mainly useful in extension update scripts. The object will subsequently be treated as a member of the extension; notably, it can only be dropped by dropping the extension.
DROP member_object This form removes a member object from the extension. This is mainly useful in extension update scripts. The object is not dropped, only disassociated from the extension.
See Section 35.15 for more information about these operations.
You must own the extension to use ALTER EXTENSION. The ADD/DROP forms require ownership of the added/dropped object as well.
extension_name The name of an installed extension.
new_version The desired new version of the extension. This can be written as either an identifier or a string literal. If not specified, ALTER EXTENSION UPDATE attempts to update to whatever is shown as the default version in the extension's control file.
new_schema The new schema for the extension.
object_name agg_name function_name operator_name The name of an object to be added to or removed from the extension. Names of tables, aggregates, domains, foreign tables, functions, operators, operator classes, operator families, sequences, text search objects, types, and views can be schema-qualified.
agg_type An input data type on which the aggregate function operates. To reference a zero-argument aggregate function, write * in place of the list of input data types.
source_type The name of the source data type of the cast.
target_type The name of the target data type of the cast.
argmode The mode of a function argument: IN, OUT, INOUT, or VARIADIC. If omitted, the default is IN. Note that ALTER EXTENSION does not actually pay any attention to OUT arguments, since only the input arguments are needed to determine the function's identity. So it is sufficient to list the IN, INOUT, and VARIADIC arguments.
argname The name of a function argument. Note that ALTER EXTENSION does not actually pay any attention to argument names, since only the argument data types are needed to determine the function's identity.
argtype The data type(s) of the function's arguments (optionally schema-qualified), if any.
left_type right_type The data type(s) of the operator's arguments (optionally schema-qualified). Write NONE for the missing argument of a prefix or postfix operator.
PROCEDURAL This is a noise word.
To update the hstore extension to version 2.0:
ALTER EXTENSION hstore UPDATE TO '2.0'; To change the schema of the hstore extension to utils:
ALTER EXTENSION hstore SET SCHEMA utils; To add an existing function to the hstore extension:
ALTER EXTENSION hstore ADD FUNCTION populate_record(anyelement, hstore); Compatibility
ALTER EXTENSION is a PostgreSQL extension.