Modifying Contiguous Time Periods in a History Table
Alex Kuznetsov is credited with a clever technique for creating a history table for SQL that is designed to store contiguous time periods and check that these time periods really are contiguous, using nothing but constraints. This is now increasingly useful with the DATE data type in SQL Server. The modification of data in this type of table isn't always entirely intuitive so Alex is on hand to give a brief explanation of how to do it.