Status rows hold timestamps, not durations. I use LEAD to measure each step, keep unfinished steps NULL, and show why zero ruins your averages.
Comparing Session SET Options Between SSMS and the Application
Fast in SSMS, slow in the app? The query may be fine and the connection settings different. Here is how to check, with nothing to set up.
Time-Limited Access: Expiring Grants With a Valid-Until Column
A ValidUntil column does nothing by itself. Here is how to make the read path enforce it, with a demo you can run.
DATEDIFF Counts Boundaries, Not Time: Getting Durations Right
A report can say one year of service after a single day. Here is why DATEDIFF does that, and what to use instead.
SQL SERVER – SmallDateTime and Precision – A Continuous Confusion
SmallDateTime and precision confuse a lot of people. I explain what the precision really is, using a Facebook question from Raghavendra.
SQL SERVER – Saturday Fun Puzzle with SQL Server DATETIME2 and CAST
A Saturday fun puzzle with DATETIME2 and CAST in SQL Server 2012. Run each script one at a time, guess the output, and learn something new.
Storing Durations and Summing Time Past 24 Hours
Use whole seconds for summing time beyond 24 hours, aggregate safely, format unlimited hours, and convert legacy time values.