Erik Darling - Advanced T-SQL Triage: The Art of Fixing Terrible Code

This one-day seminar is intended for SQL Server professionals who regularly inherit, maintain, or optimize complex and poorly written T-SQL code. It focuses on advanced query analysis and refactoring techniques, covering topics such as MERGE misuse, JOIN pitfalls, paging logic, window functions, indexed views, CTEs, user-defined functions, and dynamic SQL. Through fast-paced demos and real-world examples, participants will learn how to diagnose performance issues, understand execution plans, and rewrite slow or overly complex queries into efficient, readable, and maintainable T-SQL.

Course will take place on June 12, 2026 at Hotel International Zagreb, Miramarska cesta 24, 10000 Zagreb, Croatia.

Session abstract

Summary

You’ve seen it before: the procedure that looks like it was generated by an AI trained on Stack Overflow and despair. It’s got MERGE. It’s got RIGHT JOINs. It’s got logic so tangled you’d need a flowchart, a flashlight, and a therapist to debug it. And now… it’s your problem.

In this full-day festival of query-fixing, Erik Darling leads you through the real world mysteries of advanced T-SQL: the strange, the slow, and the occasionally cursed. You’ll tackle tangled paging logic, rescue window functions and indexed views from spools and spills, and finally learn when to keep a CTE and when to yeet it. We’ll refactor data modifications that block like linebackers, decode procedural patterns, and write dynamic SQL that’s powerful and polite.

You’ll learn when to CROSS APPLY, dig into views vs. inline TVFs, and discover why RIGHT JOIN is not simply LEFT JOIN’s syntactic twin. We’ll uncover when user-defined functions wreck your query execution plans—and how to rewrite them with flair. If you’ve ever been curious about why that query sometimes takes SO long and how to best rewrite it without just guessing, this is your playground.

Expect fast demos, big laughs, and a glorious cheat sheet to take home. Because refactoring SQL isn’t just necessary—it’s super fun when you're in the right party.

Erik Darling

I will make your SQL Server faster in exchange for money.

Erik Darling started using SQL Server after a dispute with Excel over a vlookup.
He enjoys public arguments with the optimizer, and wine photography.

Pricing

One-day seminar price	Price
Early bird price (before 01.05.2026.)	199,90€
Regular price	240,00€
*All prices are in Euro (€)

Register

Registrations for the seminar are opened until 05.06.2026. Because of limited seats and great interest please register on time if you like to attend this event.