In Locator or Deferred mode, a LOB value reference is passed from the Advanced SQL Engine to the provider. The .NET Data Provider for Teradata has access to the entire row and can support random access to every field within the row. In this mode, the .NET Data Provider for Teradata supports two additional classes namely TdBlob and TdClob which correspond to BLOB and CLOB Teradata data types. TdDataReader.GetTdBlob(Int32 i) and TdDataReader.GetTdClob(Int32 i) methods return an instance of TdBlob and TdClob respectively. TdBlob and TdClob instantiation results in additional commands (SQL queries) against the SQL Engine to retrieve the LOB field. Conceptually the retrieval of LOB data is deferred to a later time or the provider incorporates just-in-time retrieval of LOB data.