To define a storage map for a relation, you need the Oracle Rdb DEFINE privilege to the relation. You must execute this statement in a read/write transaction. If there is no active transaction and you issue this statement, Oracle Rdb starts a read/write transaction implicitly. Other users are allowed to be attached to the database when you issue the DEFINE STORAGE MAP statement. However, they are not allowed to be using the relation whose storage map is being defined.