A cursor in SQL Server took 260 milliseconds where one SELECT took 4. Why the gap exists, how to turn a loop back into a set, and the three cases where a cursor really is the right answer.
What Is In the Plan Cache and How to Look
Inspect the SQL Server plan cache, identify single-use plans and memory use, and understand what optimize for ad hoc workloads changes.
How to Read a SQL Server Execution Plan
An execution plan is SQL Server showing its working. Read it inside out, learn the six operators you actually meet, ignore the cost percentages, and compare estimated rows with actual rows instead.
What Lock Escalation Is and How to Stop It
Understand lock escalation, confirm it with evidence, and reduce its impact through smaller transactions, better access paths, and modern locking.
What Is Compatibility Level in SQL Server?
Compatibility level in SQL Server is a per-database setting, and upgrading the server does not change it. Why a restored database keeps the old level, what the setting really controls, and how to raise it without breaking a report.
What Is Locking and Blocking in SQL Server?
Locking and blocking are not the same thing, and the difference is the whole subject. I blocked a session on purpose and read it from the DMVs. Why short blocking is healthy, and why NOLOCK fixes nothing.
What Is an Index in SQL Server?
An index in SQL Server took one query from 33,517 reads to 66 on the same table. What clustered and nonclustered really mean, why every index is paid for on the way in, and how to find the ones nobody uses.