RowSet Framework

The RowSet Framework allows you to create custom instances of:

• BatchSchema
• VectorContainer
• TupleMetadata
• RecordBatch: This is effectively a fake instance of an upstream operator.

It also allows the comparison of data container in VectorContainers through the use of the RowSetComparison and RowSetUtilities.

Creating A BatchSchema

The SchemaBuilder class can be used to create an instance BatchSchema. An example of how to to this can be found the secondTest() method of ExampleTest.

Note: The BatchSchema class has limited complex type support. When possible use TupleMetadata and TupleSchema instead.

Creating TupleMetadata

TupleMetadata schema = new SchemaBuilder()
    .add(...)
    .add(...)
    .buildSchema();

Creating Test VectorContainer

VectorContainers populated with data can be created with the RowSetBuilder. In order to use it do the following:

1. Create an allocator

   BufferAllocator allocator = operatorFixture.allocator();
   

2. Create the desired BatchSchema using the SchemaBuilder.

   TupleMetadata schema = new SchemaBuilder()
           .add(...)
           .add(...)
           .buildSchema();
   

3. Create a RowSetBuilder and add records to it. Then build a RowSet.

   RowSet rowSet = new RowSetBuilder(allocator, schema)
     .addRow(110, "green", new floatArray(5.5f, 2.3f), strArray("1a", "1b"))
     .addRow(109, "blue", new floatArray(1.5f), strArray("2a"))
     .addRow(108, "red", new floatArray(-11.1f, 0.0f, .5f), strArray("3a", "3b", "3c"))
     .build();
   

4. Retrieve the VectorContainer wrapped by the RowSet.

   VectorContainer container = rowSet.container();
   

Creating A Mock Record Batch (Upstream Operator) With Data

Create a RowSet and then create a RowSetBatch

MockRecordBatch.Builder rowSetBatchBuilder = new MockRecordBatch.Builder()
    .sendData(rowSet)

Comparison Of Results

Compare Two RowSets

Use RowSetUtilities.

RowSetUtilities.verify(expectedRowSet, actualRowSet)

Compare A VectorContainer To A RowSet

You can convert a VectorContainer into a RowSet a few ways:

• If you are using an OperatorFixture the best way to do this is with:

  operatorFixture.wrap(container);
  

• When there is no selection vector you can do the following:

  RowSet rowSet = DirectRowSet.fromContainer(container);
  

• When there is a SelectionVector2.

  RowSet rowSet = IndirectRowSet.fromSv2(container, container.getSelectionVector2());
  

• When there is a SelectionVector4.

  RowSet rowSet = HyperRowSetImpl.fromContainer(container, container.getSelectionVector4());
  

After the VectorContainer is wrapped in a [RowSet](../. ./exec/java-exec/src/test/java/org/apache/drill/test/rowSet/RowSet.java) you can compare the two RowSets as usual.

End To End Example

A good example of building a RowSet and comparing results can be found in the testInitialSchema() test in TestResultSetLoaderProtocol.