if (sample > 0) {
buff.append(" LIMIT 1 SAMPLE_SIZE ").append(sample);
}
String sql = buff.toString();
Prepared command = session.prepare(sql);
ResultInterface result = command.query(0);
result.next();
for (int j = 0; j < columns.length; j++) {
int selectivity = result.currentRow()[j].getInt();
columns[j].setSelectivity(selectivity);
}
if (manual) {
db.update(session, table);
} else {