Chapter Summary


This chapter has introduced you to practical replication. You learned what replication is, what requires replication, and how to implement it.

KEY TERMS

  • Publisher

  • Subscriber

  • Distributor

  • replication agents

  • snapshot replication

  • merge replication

  • transactional replication

  • Updateable Subscribers

  • article

  • publication

  • replication configuration

First, you saw the basic idea behind replication: the Publisher/Subscriber metaphor. Basically, the Publisher is the server that creates the original data and the Subscriber is the machine that receives it.

After that, you looked at data partitioning or filtering. This enables you to trim data down, either by column or row.

You also saw the different replication configurations a firm might decide to implement. These include Central Publisher/Multiple Subscribers, Multiple Publishers/Multiple Subscribers, Multiple Publishers/Single Subscriber, and Single Publisher/Remote Distributor.

You next studied the replication agents in SQL Server. These agents are used to move data along the Publisher and Subscriber via the Distributor and keep the replication process as a whole run smoothly. These agents include the Log Reader agent, Distribution agent, Snapshot a gent, and Merge agent.

Then you looked at the different types of replication. Replication can be divided into three main categories: snapshot, transactional, and merge. Each of these models provides different capabilities and levels of autonomy and Transactional consistency when used in an application on a site. To determine which replication is best suited for your needs, you need to consider three factors: site autonomy, transactional consistency, and latency.

EXAM TIP

Reviewing Replication When reviewing this chapter before sitting the exam, be sure to know the different replication configurations available, the different types of replication, and the components in the Publisher/Subscriber metaphor, along with the description, uses, and benefits of each. Most questions on the exam relating to replication are scenario-based; a good example of this is the first exam question at the end of this chapter.


This chapter also discussed some of the ideas behind Updating Subscribers. Using Updating Subscribers, as the name implies, gives the Subscriber the power to update or modify data when it is replicated. This option can be used with snapshot replication and transactional replication. You can use two configurations to enable Updateable Subscribers: immediate updating and queued updating.

You saw how to actually implement replication in your database. The first step is creating a Distributor and Publisher. Then you create a publication and set articles within that publication.

And finally you learned how to define the various Subscribers who subscribe to a publication. SQL Server 2000 makes implementing replication simpler with the easy-to-use wizards provided.

As you have seen, replication is quite an involved and diverse process that requires a lot of planning and careful consideration as well as ongoing monitoring. Monitoring replication as well as other database activity is an important aspect of working with SQL Server from day to day. It will also be a significant topic on the exam. The next chapter looks at all aspects of monitoring and fine-tuning SQL Server processes.



MCSE Training Guide (70-229). Designing and Implementing Databases with MicrosoftR SQL ServerT 2000 Enterprise Edition
MCSE Training Guide (70-229). Designing and Implementing Databases with MicrosoftR SQL ServerT 2000 Enterprise Edition
ISBN: N/A
EAN: N/A
Year: 2003
Pages: 228

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