private ImmutablePair<String, TableScanOperator> verifyOnlyOneTableScanOperator(MapWork mapWork) {

      // Eliminate MR plans with more than one TableScanOperator.

      Map<String, Operator<? extends OperatorDesc>> aliasToWork = mapWork.getAliasToWork();
      if ((aliasToWork == null) || (aliasToWork.size() == 0)) {
        setNodeIssue("Vectorized map work requires work");
        return null;
      }
      int tableScanCount = 0;
      String alias = "";
      TableScanOperator tableScanOperator = null;
      for (Entry<String, Operator<? extends OperatorDesc>> entry : aliasToWork.entrySet()) {
        Operator<?> op = entry.getValue();
        if (op == null) {
          setNodeIssue("Vectorized map work requires a valid alias");
          return null;
        }
        if (op instanceof TableScanOperator) {
          tableScanCount++;
          alias = entry.getKey();
          tableScanOperator = (TableScanOperator) op;
        }
      }
      if (tableScanCount > 1) {
        setNodeIssue("Vectorized map work only works with 1 TableScanOperator");
        return null;
      }
      return new ImmutablePair<>(alias, tableScanOperator);
    }
Decimal types can be specified with different precision and scales e.g. decimal(10,5),
as opposed to other data types which can be represented by constant strings.
The regex matches only the {@link serdeConstants#DECIMAL_TYPE_NAME} prefix of the type.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/physical/Vectorizer.java