private void runMergeStatement(String tableName, List<String> values) throws Exception {
    dropTables(driver, "merge_source");
    executeStatementOnDriver("CREATE TABLE merge_source(id int,value string) STORED AS ORC", driver);
    StringBuilder sb = new StringBuilder();
    for (String value : values) {
      sb.append("(");
      sb.append(value);
      sb.append("),");
    }
    executeStatementOnDriver("INSERT INTO merge_source VALUES " + sb.toString().substring(0, sb.length() - 1), driver);
    executeStatementOnDriver("MERGE INTO " + tableName
        + " AS T USING merge_source AS S ON T.ID = S.ID WHEN MATCHED AND (T.value != S.value AND S.value IS NOT NULL) THEN UPDATE SET value = S.value WHEN NOT MATCHED THEN INSERT VALUES (S.ID, S.value)",
        driver);
    dropTables(driver, "merge_source");
  }
After running insert overwrite, followed by a minor compaction, major compaction was failing because minor
compaction was resulting in deltas named delta_1_y.
itests/hive-unit/src/test/java/org/apache/hadoop/hive/ql/txn/compactor/TestCrudCompactorOnTez.java