Microsoft KB Archive/181092

{| = FAQ: Remote Data Service (RDS) Frequently Asked Questions =
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ID: q181092

The information in this article applies to:


 * Remote Data Service for ADO versions 1.1, 1.5

SUMMARY
This is a list of frequently asked questions for Remote Data Service (RDS).

MORE INFORMATION
1. Q. What is Remote Data Service (RDS) for ActiveX Data Objects (ADO)?

A. Remote Data Service (RDS) is used to transport Active Data Object recordsets from a server to a client computer. The resulting recordset is cached on the client computer and disconnected from the server.

2. Q. Where can I get Remote Data Service (RDS) for ADO?

A. RDS is part of the Microsoft Data Access Components (MDAC). RDS can be obtained from the Microsoft Universal Data Access Web page located at:

http://www.microsoft.com/data/

The RDS 1.5 server components are also installed with Internet Information Server (IIS) 4.0 and with the RDS 1.5 client components install of Internet Explorer (IE) 4.0.

3. Q. What are the different versions of the RDS client and server components?

A. RDS currently consists of two client versions and one server version. The client versions are 1.1 and 1.5. The server version is 1.5.

4. Q. What are the differences between the two client versions of the RDS software?

A. RDS version 1.1 is for use with clients that are using Internet Explorer 3.02. RDS version 1.5 is distributed with Internet Explorer version 4.0. Version 1.5 of the RDS client components include additional features for use with the RDS.DataControl. Please refer to the RDS documentation for more details. 5. Q: How are the RDS clients distributed to the client computers? A. If the client computer is using Internet Explorer (IE) version 3.02 the RDS 1.1 client components are distributed with the Msadc11.cab file that is installed on the server computer when MDAC 1.5 is installed. When installing MDAC 1.5 the RDS version 1.1 files do not install unless specifically selected during the MDAC 1.5 setup.

6. Q. If I am creating a Custom Business Object (typically written with  Visual Basic) on a different computer than the RDS server what files are required to compile the business object?

A. You must have the RDS server files installed on the computer that you use for developing your Custom Business Object. Internet Information Server or Personal Web Server is not needed to compile the Custom Business object. However, Internet Information Server or Personal Web Server is necessary for a fully functional test of the component.

7. Q. When the documentation is referencing features of 1.5 is it referring to the server or client components?

A. The features that are discussed in the documentation are available with the 1.5 client side components. If you are using the 1.5 server components and the 1.1 client components you will not have all of the 1.5 functionality described in the documentation.

8. Q. Is Windows NT Server necessary to run RDS as a server?

A. No, Windows NT Workstation and Windows 95 Personal Web Services also work. However, Windows NT Server is the recommended platform for high volume Web servers.

9. Q. Where is the documentation that comes with RDS?

A. The documentation that comes with RDS is in html format and can be  located at C:\Program Files\Common Files\System\MSADC\Docs. Selecting Default.htm opens the help file. If you install MDAC 1.5c (available  after 12/18/97 from the web), you also get an entry in the Program Files menu for "Microsoft Data Access Components 1.5" if you enabled the documentation for ADO and RDS when installing the MDAC components.

10. Q. What is a Three Tiered application? Why must I use one with RDS?

A. This approach separates the various components of a client/server System into three "tiers" as described below:

Client tier - a local computer on which either a Web browser displays a Web page that can display and manipulate data from a remote data source, or (in non Web-based applications) a stand-alone compiled front-end application.

Middle tier - a Microsoft Windows NT Server computer that hosts components that encapsulate an organization's business rules. Middle-tier components can either be Active Server Page scripts executed on Internet Information Server, or (in non Web-based     applications) compiled DLL's or executables.

Data source tier - a computer hosting a database management system (DBMS), such as a Microsoft SQL Server database. (In a two-tier     application, the middle-tier and data source tier are combined.)

These tiers do not necessarily correspond to physical locations on the network. For example, all three tiers may exist on only two computers. One computer could be a Windows 95 computer running Internet Explorer 4.0 as its browser. The second computer could be a Windows NT Server computer running both Internet Information Server and Microsoft SQL Server.

This method of designing applications gives you greater flexibility when deploying processes and data on the network for maximum performance and ease of maintenance.

By using a three-tiered design, you are simplifying the deployment of  your RDS application. The middle tier is used to host your Custom Business Object. By doing this you will not have to distribute the ADODB object, ODBC 3.5, or database drivers to the client computers.

Once the user enters a request, the client-side RDS components send the query to the Web server. The server-side RDS components process the request and send the request to the DBMS. The DBMS responds to the request, sending back the data. The RDS components on the Web server transform that data into an ADO Recordset object. The data is converted for transport to the client and sent back across the network to the client computer.

You may refer to the RDS 1.5 documentation - Microsoft Remote Data Service/Remote Data Service Developer's Guide/Understanding Remote Data Service Applications/Three-Tiered Applications for further explanation.

11. Q. What is the difference between the ADODB and ADOR objects?

A. The ADODB Library contains additional server side objects (Connection, Command, Error, Parameters and so forth.) These are best used within server side components to communicate with the database. In   order to use this functionality on the client you would have to    distribute additional files and ODBC 3.5 to each client computer. The ADODB functionality is not distributed with the RDS Client components.

The ADOR Library is a lighter weight client that allows for the manipulation of an existing recordset on the client. It does not include the Connection, Command, Error, or Parameters commands. The ADOR functionality is distributed with the RDS client components.

12. Q. Can the full ADODB recordset be used to transfer data over http? If   so, why is there an ADOR recordset?

A. No, you need RDS to do the caching and remoting over http. The RDS proxy is used to remotely marshal an ADOR disconnected recordset across http. RDS is the container that does the caching and remoting of the ADOR recordset.

13. Q. Can I use a User data source name (DSN) when using RDS?

A. No, you must use a System or File ODBC DSN when using RDS. The Anonymous user logging on through IIS can not view User DSNs.

14. Q. Can the RDS Data Control be placed on a Visual Basic Form such as   those in the Visual Basic (VB) toolbox?

A. No, the RDS Control is not a visible control. You must Programmatically create the control.

15. Q. I am having trouble creating my Business Object on the server computer from the client. What could I be doing wrong?

A. Check to make sure the Business Object is registered on the server computer and added to the ADCLaunch registry key shown below:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\ W3SVC\Parameters\ADCLaunch]

16. Q. In a previous version of RDS I was using the AdvancedDataControl, AdvancedDataFactory and the AdvancedDataSpace. What happened to these objects?

A. The objects have new names. The AdvancedDataControl is now the RDS.DataControl, the AdvancedDataFactory is now RDSServer.DataFactory, and the AdvancedDataSpace is now RDS.DataSpace.