Readers took my Interesting Interview Questions test seriously. See who got the correct answer, and why good T-SQL mattered more than the schema.
Percent Change Between Rows: Handling Zero and NULL Safely
One zero month can kill a revenue report. Here is how to get percent change without errors or lies.
Breaking Ties Deterministically: Why ORDER BY Needs a Tie-Breaker
Tied scores can come back in any order, which breaks paging. Here is the one column that fixes it.
An Upgrade Checklist That Fits on One Page
An upgrade checklist that fits on one page keeps before, during, and after checks visible, including backups, logins, jobs, clients, and rollback.
Comparing Float Values: Why 0.1 + 0.2 Is Not 0.3 in SQL Server
Why does 0.1 + 0.2 miss 0.3 only when float is involved? A few tiny queries show the hidden digits, the drifting sum and two clean fixes.
SQL SERVER – Interesting Observation – Use of Index and Execution Plan
Three AdventureWorks examples show how the Query Optimizer picks an index, what happens when you force one, and how that changes the index and execution plan.
Skills That Make a DBA Hard to Replace
The skills that make a DBA hard to replace combine tested recovery, careful performance work, useful automation, and clear communication.