@JsonIgnore
public MajorType getMajorType() {
MajorType.Builder b = MajorType.newBuilder();
b.setMode(mode);
b.setMinorType(minorType);
if (precision != null) b.setPrecision(precision);
if (width != null) b.setWidth(width);
if (scale != null) b.setScale(scale);
return b.build();
}
// The output table's column names always follow the left table,
// where the output type is chosen based on DRILL's implicit casting rules
private void inferOutputFields() {
outputFields = Lists.newArrayList();
leftSchema = leftSide.getRecordBatch().getSchema();
rightSchema = rightSide.getRecordBatch().getSchema();
Iterator<MaterializedField> leftIter = leftSchema.iterator();
Iterator<MaterializedField> rightIter = rightSchema.iterator();
int index = 1;
while (leftIter.hasNext() && rightIter.hasNext()) {
MaterializedField leftField = leftIter.next();
MaterializedField rightField = rightIter.next();
if (hasSameTypeAndMode(leftField, rightField)) {
outputFields.add(MaterializedField.create(leftField.getPath(), leftField.getType()));
} else {
// If the output type is not the same,
// cast the column of one of the table to a data type which is the Least Restrictive
MinorType outputMinorType;
if (leftField.getType().getMinorType() == rightField.getType().getMinorType()) {
outputMinorType = leftField.getType().getMinorType();
} else {
List<MinorType> types = Lists.newLinkedList();
types.add(leftField.getType().getMinorType());
types.add(rightField.getType().getMinorType());
outputMinorType = TypeCastRules.getLeastRestrictiveType(types);
if (outputMinorType == null) {
throw new DrillRuntimeException(
"Type mismatch between "
+ leftField.getType().getMinorType().toString()
+ " on the left side and "
+ rightField.getType().getMinorType().toString()
+ " on the right side in column "
+ index
+ " of UNION ALL");
}
}
// The output data mode should be as flexible as the more flexible one from the two input
// tables
List<DataMode> dataModes = Lists.newLinkedList();
dataModes.add(leftField.getType().getMode());
dataModes.add(rightField.getType().getMode());
DataMode dataMode = TypeCastRules.getLeastRestrictiveDataMode(dataModes);
MajorType.Builder builder = MajorType.newBuilder();
builder.setMinorType(outputMinorType);
builder.setMode(dataMode);
outputFields.add(MaterializedField.create(leftField.getPath(), builder.build()));
}
++index;
}
assert !leftIter.hasNext() && !rightIter.hasNext()
: "Mis-match of column count should have been detected when validating sqlNode at planning";
}
