ALTER SCHEMA changes the definition of a schema.
You must own the schema to use ALTER SCHEMA. To rename a schema you must also have the CREATE privilege for the database. To alter the owner, you must also be a direct or indirect member of the new owning role, and you must have the CREATE privilege for the database. (Note that superusers have all these privileges automatically.)
The name of an existing schema.
The new name of the schema. The new name cannot begin with pg_, as such names are reserved for system schemas.
The new owner of the schema.