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SQL Server Overview

This section covers the SQL Server topics most likely to come up in a developer interview, with particular focus on stored procedures, indexing, and query performance — the areas where developers who rely on DBAs can have knowledge gaps.

Topics in This Section

  • Joins — INNER, LEFT, RIGHT, FULL OUTER, CROSS, and SELF joins with real examples
  • Stored Procedures — Writing, optimizing, and best practices
  • Indexes — Clustered, nonclustered, covering, and composite indexes
  • Query Optimization — Practical techniques to make queries faster
  • Execution Plans — Reading and acting on execution plans (VS Code MSSQL / DataGrip)
  • Parameter Sniffing — What it is and how to fix it

Key SQL Server Concepts to Know Cold

T-SQL vs ANSI SQL — SQL Server uses Transact-SQL (T-SQL), Microsoft's extension of ANSI SQL. It adds control flow, local variables, error handling (TRY/CATCH), and more.

Query lifecycle: Parse → Bind → Optimize → Execute. The optimizer generates an execution plan, which is cached for reuse. Understanding this is key to explaining why stored procedures perform well.

SQL Server editions commonly used in enterprise: Standard, Enterprise, Developer (free, same features as Enterprise — great for local dev).

Useful Shortcuts on macOS

Note: Azure Data Studio was retired February 28, 2026. Use VS Code + MSSQL extension or DataGrip.

VS Code MSSQL Extension

Action How
Execute query Cmd + Shift + E or click ▶ in toolbar
Run with actual execution plan Right-click → Run Query with Actual Execution Plan
Show estimated execution plan Right-click → Explain Current Statement
Comment/uncomment lines Cmd + /
Connect to server Click the server name in the status bar at the bottom

DataGrip

Action How
Execute query / selection Cmd + Enter
Run with actual execution plan Right-click → Explain Plan → Explain Analyzed
Show estimated execution plan Right-click → Explain Plan → Explain Plan or Cmd + Shift + E
Comment/uncomment lines Cmd + /
Reformat SQL Cmd + Alt + L