The TSQL aggregate function SUM() gives a number based on the addition of the values of multiple rows to each other. Do the same thing but with multiplication instead of addition.

One of the more popular counters used by DBAs to monitor SQL Server performance, the Buffer Cache Hit Ratio, is useless as a predictor of imminent performance problems. Worse, it can be misleading. Jonathan Kehayias demonstrates this convincingly with some simple tests.

This article takes a closer look at SQL Server getdate() and sysdatetime() functions.

A benefit of using computed columns is that they can save developers from having to write calculation logic at the application layer; at the table level, the application can simply reference the computed column. In addition, performance can be improved by persisting a computed column and building an index on it.

To kick off a series of DBA worst case scenarios, we asked Phil Factor to confess. He came up with a classic: The mistaken belief that a backup WITH CHECKSUM guaranteed a good backup that could be restored, and the ensuing disaster.