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SQL Server, revised properly

Indexes, T-SQL, transactions and performance — in plain language, with real queries. 73 questions across 7 modules in 4 categories, plus a cheat sheet and flashcards for the last hour before the call.

0 of 7 modules done

How to use this

The fast route

Pick a category in the sidebar — it expands to show only its modules. In each module, the big questions end with a 30-second interview answer box: that's the bit to say out loud. The compact rows are there so the term doesn't catch you off guard.

If you have…Do this
1 dayAll four categories in order — it's only 7 modules.
3 hoursModules 01 (indexes), 05 (transactions & isolation), 07 (performance).
1 hourCheat sheet → the six predict the output boxes → the Trap boxes.
20 minutesCheat sheet, printed. The "15 things to be sure of" table twice.

What they actually ask

For a .NET role the SQL round concentrates on four things: indexes (clustered vs non-clustered, composite column order, why an index can hurt), writing the query (delete duplicates, ROW_NUMBER vs RANK, CTEs), transactions and isolation (ACID, dirty vs phantom reads, NOLOCK), and troubleshooting (a slow query, a deadlock, parameter sniffing). Those are modules 01, 03, 05–06 and 07.

Predict the output

Where SQL Server surprises people — @@IDENTITY after a trigger, a dirty read under NOLOCK, ROW_NUMBER vs RANK with ties, a deadlock traced step by step — you get the code with a hidden answer. Work it out first, then click Show the answer. Every code block also has a Copy button so you can run it in SSMS.

Search

The sidebar search covers all 73 questions from any page — try "SARGable", "phantom", "sniffing", "NOLOCK". Results link straight to the answer.