Queues in the DB are so common that in MSSQL they made it a first class feature: SQL Server Service Broker. Using it is an XML and T-SQL nightmare, but since i

Queues in the DB are so common that in MSSQL they made it a first class feature: SQL Server Service Broker. Using it is an XML and T-SQL nightmare, but since it guarantees in-order, only once delivery, and supports routing and in-DB worker activation, you can build some really robust and powerful stuff with it. MySpace used it to keep their partitioned databases in sync: http://www.microsoft.com/casestudies/Case_Study_Detail.aspx?CaseStudyID=4000004532 http://www.microsoft.com/casestudies/Case_Study_Detail.aspx?...