Replication Improvements

SQL Server 2000 makes many improvements to replication, its service for automatically copying data among database servers. Replication allows companies to distribute or roll up information across servers (e.g., collect financial data from branch offices for central reporting) and to support mobile users who need offline database access (e.g., sales reps who take orders on a laptop). SQL Server provides numerous options for replication, which administrators choose among depending on how many servers contribute replicated data, the volume of data, how frequently the data change, and the quality of connections among servers.

Replication Background

SQL Server replication copies a replicated data set (called a publication) from a central server (the publisher) to a set of subscriber servers. Initially, the subscriber receives a file called a snapshot with a complete copy of the publication. Thereafter, publishers update subscribers’ copies by one of three methods: send entire database copies (snapshot replication), send a list of transactions that ran against the database since the last update (transactional replication), or send changed database rows (merge replication).