The CData ADO.NET Provider for Apache Impala enables you to take advantage of the bulk load support in Apache Impala through ApacheImpalaDataAdapters. You can use the Batch API to execute related SQL data manipulation statements simultaneously. The provider translates all SQL queries in the batch into a single request.

Using the ADO.NET Batch API

Performing a batch update consists of the following basic steps:

1. Define custom parameterized SQL statements in ApacheImpalaCommand objects.
2. Set the UpdatedRowSource property of the ApacheImpalaCommand object to "UpdateRowSource.None".
3. Assign the ApacheImpalaCommand objects to the ApacheImpalaDataAdapter.
4. Add the parameters to the command.
5. Call the ApacheImpalaDataAdapter's Update method. Pass in a DataSet or DataTable containing your changes.

Controlling Batch Size

Depending on factors such as the size of the request, your network resources, and the performance of the server, you may gain performance by executing several smaller batch requests. You can control the size of each batch by setting the ApacheImpalaDataAdapter's UpdateBatchSize property to a positive integer.

Bulk INSERT

The following code prepares a single batch that inserts records in bulk. The example executes a batch INSERT of new DataRows, which have the "Added" state.

C#

ApacheImpalaDataAdapter adapter = new ApacheImpalaDataAdapter();

using (ApacheImpalaConnection conn = new ApacheImpalaConnection("Server=127.0.0.1;Port=21050;")) {
  conn.Open();
  adapter.InsertCommand = conn.CreateCommand();
  adapter.InsertCommand.CommandText = "INSERT INTO [CData].[Default].Customers (CompanyName) VALUES (@CompanyName)";
  adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None;
  adapter.InsertCommand.Parameters.Add("@CompanyName", "CompanyName");

  DataTable batchDataTable = new DataTable();
  batchDataTable.Columns.Add("CompanyName", typeof(string));
  batchDataTable.Rows.Add("Jon Deere");
  batchDataTable.Rows.Add("RSSBus Inc.");
  adapter.UpdateBatchSize = 2;
  adapter.Update(batchDataTable);
}

VB.NET

 
Dim adapter As New ApacheImpalaDataAdapter()

Using conn As New ApacheImpalaConnection("Server=127.0.0.1;Port=21050;")
  conn.Open()
  adapter.InsertCommand = conn.CreateCommand()
  adapter.InsertCommand.CommandText = "INSERT INTO [CData].[Default].Customers (City) VALUES (@CompanyName)"
  adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None
  adapter.InsertCommand.Parameters.Add("@CompanyName", "CompanyName")

  Dim batchDataTable As New DataTable()
  batchDataTable.Columns.Add("CompanyName", GetType(String))
  batchDataTable.Rows.Add("RSSBus Inc.")
  batchDataTable.Rows.Add("Jon Deere")
  adapter.UpdateBatchSize = 2
  adapter.Update(batchDataTable)
End Using