1.3 Overview

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The Remote Data Services (RDS) Transport Protocol is an application-level protocol for distributed applications. RDS Transport Protocol specifies a protocol allowing for the remote query and manipulation of data on a remote server. To facilitate data operations, it specifies how a remote method and its parameters are represented in an RDS message for transmission by way of an HTTP request to a server for execution. It also specifies how the results of an invoked method are represented in a message for transmission back to the client by way of the HTTP response. Finally, it specifies the data-centric messages used for data query and manipulation as well as their associated RecordSets.

The core data-centric messages used in an RDS Transport Protocol server are as follows:

  • Execute - Provides a method to execute a complex SQL command and return a RecordSet.

  • Query - Provides a method to execute a simple parameterless SQL query command and return a RecordSet.

  • Synchronize - Provides a method for an RDS Transport Protocol client to synchronize data changes from the client to the server.

The following diagram depicts a typical flow of communication in the RDS Transport Protocol. The client uses Query to populate a client-side RecordSet and uses data from the RecordSet for processing. The client-side RecordSet tracks changes made to the data. Only these changes are then transmitted back to the server.<2>

Communication flow in the RDS Transport Protocol

Figure 1: Communication flow in the RDS Transport Protocol

For more information, refer to the following sections:

  • Section 2.1: General overview on how RDS messages relate to HTTP.

  • Sections 2.2.2 through 2.2: The Backus-Naur Form (BNF) syntax and encoding of the RDS messages.

  • Section 2.2.3: The RDS messages specific to data query and manipulation.

  • Section 2.2: The syntax and encoding of the resulting RecordSets.

    Note The RDS Transport Protocol was developed to support communication of tabular data between systems; specifically, Microsoft used the RDS Transport Protocol in early versions of Windows SharePoint Services. This method of transporting tabular data has been superseded by SOAP and the Distributed Component Object Model (DCOM), and is no longer used by Windows SharePoint Services. Microsoft does not use the RDS Transport Protocol within the Windows operating systems.