Chapter 6 Creating Multiuser Applications

Microsoft Jet supports the network environment with a variety of services designed to make your life as a developer easier. Microsoft Jet 3.5 boasts improved multiuser performance and increased concurrency (the simultaneous availability of the same sets of data and objects to multiple users).

To implement multiuser applications that run smoothly using Microsoft Jet, you should be familiar with the engine’s multiuser model. Moving an existing single-user application to a multiuser environment is not always a simple port, and you should plan ahead and address the issues discussed in this chapter. A multiuser application should be designed as such from the ground up, with the database engine’s functionality in mind. This chapter guides you through these issues and shows you how to effectively use Microsoft Jet to manage resources and minimize contention for data and objects. (Contention occurs when two or more users are attempting to modify the same data or object.)

See Also For more information about using Microsoft Jet in a client/server configuration, see Chapter 9, “Developing Client/Server Applications.” For more information about performance in Microsoft Jet 3.5, see Chapter 13, “Optimizing Performance.”

File-Server vs. Client/Server

The Microsoft Jet Multiuser Model

Managing Shared Databases

Microsoft Jet Locking Architecture

Handling Conflicts

Other Issues in Multiuser Design

Optimizing Multiuser Applications

Sharing Microsoft Jet Databases on the Web

Using the Code Examples in This Chapter

You can use the code examples in this chapter to help you understand the concepts discussed, or you can modify them and use them in your own applications.

The code examples are located in the JetBook\Samples subfolder on the companion CD-ROM. The code examples for Microsoft Access 97 are in JetSamples.mdb, and the corresponding code examples for Microsoft Visual Basic version 5.0 and other applications that support Visual Basic for Applications are referenced in JetSamples.vbp. Both JetSamples.mdb and JetSamples.vbp use tables and queries in NorthwindTables.mdb, also located in the JetBook\Samples subfolder.

To use the code examples, copy the sample files to your hard disk. Be sure to copy NorthwindTables.mdb as well so that you can use the code examples to work with data.

See Also For more information about copying and using the code examples from the companion CD-ROM, see “Using the Companion CD-ROM” in the Preface.