Batch Processing
The CData ADO.NET Provider for Greenplum enables you to take advantage of the bulk load support in Greenplum through GreenplumDataAdapters. You can use the Batch API to execute related SQL data manipulation statements simultaneously.
Using the ADO.NET Batch API
Performing a batch update consists of the following basic steps:
- Define custom parameterized SQL statements in GreenplumCommand objects.
- Set the UpdatedRowSource property of the GreenplumCommand object to "UpdateRowSource.None".
- Assign the GreenplumCommand objects to the GreenplumDataAdapter.
- Add the parameters to the command.
- Call the GreenplumDataAdapter'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 GreenplumDataAdapter'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#
GreenplumDataAdapter adapter = new GreenplumDataAdapter(); using (GreenplumConnection conn = new GreenplumConnection("User=user;Password=admin;Database=dbname;Server=127.0.0.1;Port=5432")) { conn.Open(); adapter.InsertCommand = conn.CreateCommand(); adapter.InsertCommand.CommandText = "INSERT INTO \"template1\".\"public\".Orders (ShipCity) VALUES (@ShipCity)"; adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None; adapter.InsertCommand.Parameters.Add("@ShipCity", "ShipCity"); DataTable batchDataTable = new DataTable(); batchDataTable.Columns.Add("ShipCity", typeof(string)); batchDataTable.Rows.Add("Raleigh"); batchDataTable.Rows.Add("New York"); adapter.UpdateBatchSize = 2; adapter.Update(batchDataTable); }
VB.NET
Dim adapter As New GreenplumDataAdapter()
Using conn As New GreenplumConnection("User=user;Password=admin;Database=dbname;Server=127.0.0.1;Port=5432")
conn.Open()
adapter.InsertCommand = conn.CreateCommand()
adapter.InsertCommand.CommandText = "INSERT INTO \"template1\".\"public\".Orders (ShipName) VALUES (@ShipCity)"
adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None
adapter.InsertCommand.Parameters.Add("@ShipCity", "ShipCity")
Dim batchDataTable As New DataTable()
batchDataTable.Columns.Add("ShipCity", GetType(String))
batchDataTable.Rows.Add("New York")
batchDataTable.Rows.Add("Raleigh")
adapter.UpdateBatchSize = 2
adapter.Update(batchDataTable)
End Using
Bulk Update
A batch update additionally requires the primary key of each row to update. The following example executes a batch for all DataRow records with a "Modified" state:
C#
GreenplumDataAdapter adapter = new GreenplumDataAdapter(); using (GreenplumConnection conn = new GreenplumConnection("User=user;Password=admin;Database=dbname;Server=127.0.0.1;Port=5432")) { conn.Open(); adapter.UpdateCommand = conn.CreateCommand(); adapter.UpdateCommand.CommandText = "UPDATE \"template1\".\"public\".Orders SET ShipCity=@ShipCity WHERE Id=@Id"; adapter.UpdateCommand.Parameters.Add("@ShipCity", "ShipCity"); adapter.UpdateCommand.Parameters.Add("@Id", "Id"); adapter.UpdateCommand.UpdatedRowSource = UpdateRowSource.None; DataTable batchDataTable = new DataTable(); batchDataTable.Columns.Add("ShipCity", typeof(string)); batchDataTable.Rows.Add("Raleigh"); batchDataTable.Rows.Add("New York"); adapter.UpdateBatchSize = 2; adapter.Update(dataTable); }
VB.NET
Dim adapter As New GreenplumDataAdapter()
Using conn As New GreenplumConnection("User=user;Password=admin;Database=dbname;Server=127.0.0.1;Port=5432")
conn.Open()
adapter.UpdateCommand = conn.CreateCommand()
adapter.UpdateCommand.CommandText = "UPDATE \"template1\".\"public\".Orders SET ShipCity=@ShipCity WHERE Id=@Id"
adapter.UpdateCommand.Parameters.Add("@ShipCity", "ShipCity")
adapter.UpdateCommand.Parameters.Add("@Id", "Id")
adapter.UpdateCommand.UpdatedRowSource = UpdateRowSource.None
Dim batchDataTable As New DataTable()
batchDataTable.Columns.Add("ShipCity", GetType(String))
batchDataTable.Rows.Add("New York")
batchDataTable.Rows.Add("Raleigh")
adapter.UpdateBatchSize = 2
adapter.Update(dataTable)
End Using