Criar extensão funciona no modo de usuário único no postgres?

/*
 * Decide whether to create an array type over the relation's rowtype. We
 * do not create any array types for system catalogs (ie, those made
 * during initdb). We do not create them where the use of a relation as
 * such is an implementation detail: toast tables, sequences and indexes.
 */
if (IsUnderPostmaster && (relkind == RELKIND_RELATION ||
                          relkind == RELKIND_VIEW ||
                          relkind == RELKIND_MATVIEW ||
                          relkind == RELKIND_FOREIGN_TABLE ||
                          relkind == RELKIND_COMPOSITE_TYPE))
    new_array_oid = AssignTypeArrayOid();