Data Sets

Drill includes several data sets for testing, and also provides some tools for generating test data sets.

Bundled Data Sets

There are three primary data sets bundled with drill for testing:

• Sample Data: These are parquet files in the sample-data folder.
• Resource Data: These are data files in the exec/java-exec/src/test/resources folder.
• TPCH Data: These are trimmed down versions of the tpch data sets. They are retrieved and bundled in the contrib/data maven submodule. They are also accessible on [Apache Drill's S3 bucket](http://apache-drill.s3.amazonaws.com/files/sf-0 .01_tpc-h_parquet.tgz). When unit tests are running all of the files in these data set are available from the classpath storage plugin. The tpch files include:
  • customer.parquet
  • lineitem.parquet
  • nation.parquet
  • orders.parquet
  • part.parquet
  • partsup.parquet
  • region.parquet
  • supplier.parquet

Using Sample Data in Unit Tests

ClusterFixture

See seventhTest() in ExampleTest for an example of how to do this.

BaseTestQuery (Deprecated Use ClusterFixture or ClusterTest Instead)

When using the BaseDirTestWatcher you can make sample-data accessible from the dfs storage plugin by doing the following:

public class TestMyClass {
  @ClassRule
  public static final BaseDirTestWatcher dirTestWatcher = new BaseDirTestWatcher();
  
  @BeforeClass
  public static void setupFiles() {
    dirTestWatcher.copyFileToRoot(Paths.get("sample-data", "region.parquet"));
  }
  
  @Test
  public void simpleTest() {
     // dfs.root.`sample-data/region.parquet` will be accessible from my test
  }
}

Or if you are extending BaseTestQuery

public class TestMyClass extends BaseTestQuery {
  @BeforeClass
  public static void setupFiles() {
    dirTestWatcher.copyFileToRoot(Paths.get("sample-data", "region.parquet"));
  }
  
  @Test
  public void simpleTest() {
     // dfs.root.`sample-data/region.parquet` will be accessible from my test
  }
}

Using Resource Data in Unit Tests

ClusterFixture

See sixthTest() in ExampleTest for an example of how to do this.

BaseTestQuery (Deprecated Use ClusterFixture or ClusterTest Instead)

When using the BaseDirTestWatcher you can make data from exec/java-exec/src/test/resources accessible from the dfs storage plugin by doing the following:

public class TestMyClass {
  @ClassRule
  public static final BaseDirTestWatcher dirTestWatcher = new BaseDirTestWatcher();
  
  @BeforeClass
  public static void setupFiles() {
    dirTestWatcher.copyResourceToRoot(Paths.get("join", "empty_part"));
  }
  
  @Test
  public void simpleTest() {
     // src/test/resources/join/empty_part is acessible at dfs.root.`join/empty_part` from my test
  }
}

Or if you are extending BaseTestQuery

public class TestMyClass extends BaseTestQuery {
  @BeforeClass
  public static void setupFiles() {
    dirTestWatcher.copyResourceToRoot(Paths.get("join", "empty_part"));
  }
  
  @Test
  public void simpleTest() {
     // src/test/resources/join/empty_part is acessible at dfs.root.`join/empty_part` from my test
  }
}

Using TPCH Data in Unit Tests

TPCH data is accessible via the classpath storage plugin

cp.`tpch/customer.parquet`

Generating Data Sets

There are a few ways to generate data for testing:

• JsonFileBuilder
• Inline Mock Scanner
• MockRecordReader

Json

The JsonFileBuilder can be used to create json data files. It's useful for creating data files for both integration and unit tests. An example of using the JsonFileBuilder can be found in secondTest() in ExampleTest.

Inline Mock Scanner

The MockScanner is a special scanner that generates data for a query. It can only be used for integration testing.

Using In A Query

The MockScanner can be used directly from sql queries. An example can be found in thirdTest() in ExampleTest.

The example uses the following query

SELECT id_i, name_s10 FROM `mock`.`employees_5`

The select columns encode the name and type of the columns to generate. The table name also encodes the number of records to generate.

• Columns: Columns in the sql query have the form (name)_(type). (name) is the name that is assigned to a column. (type) is the data type of the column. Valid types are:
  • Use i for specifying an integer column.
  • Use s(n) for specifying a string column. Replace (n) with an integer which specifies the number of character in each varchar record.
• Table: Tables in the sql query have the form (name)_(n). Where (name) is the name of the source table. (n) specifies the number of records to generate for the source table.