public int getUniqueCount() {
accessCheck();
if ( m_unique == -1 && m_dynamic ) {
Index idx = m_table.getIndex(m_field);
if ( idx != null ) {
m_unique = idx.uniqueCount();
} else {
m_unique = DataLib.uniqueCount(m_table.tuples(), m_field);
}
}
return m_unique;