</para>
<para>
- The validator function is responsible for validating options given in the
- <command>CREATE FOREIGN DATA WRAPPER</command>, <command>CREATE
- SERVER</command> and <command>CREATE FOREIGN TABLE</command> commands.
+ The validator function is responsible for validating options given in
+ <command>CREATE</command> and <command>ALTER</command> commands for its
+ foreign data wrapper, as well as foreign servers, user mappings, and
+ foreign tables using the wrapper.
The validator function must be registered as taking two arguments, a text
array containing the options to be validated, and an OID representing the
type of object the options are associated with (in the form of the OID
- of the system catalog the object would be stored in). If no validator
- function is supplied, the options are not checked at object creation time.
+ of the system catalog the object would be stored in, either
+ <literal>ForeignDataWrapperRelationId</>,
+ <literal>ForeignServerRelationId</>,
+ <literal>UserMappingRelationId</>,
+ or <literal>ForeignTableRelationId</>).
+ If no validator function is supplied, options are not checked at object
+ creation time or object alteration time.
</para>
<para>