How to find the query that ran at 3 a.m. after the fact. It uses nothing but what SQL Server 2025 keeps on its own. I planted a culprit, gave it eight disguises and buried it in four hundred innocent lookups. Then I tracked it down with Query Store. This is the poster.
SQL Server Deadlock, Slow-Cooked: A Recipe That Serves Two Sessions
A SQL Server deadlock, written up the way a recipe card is written. Ingredients, prep, method, and what to do when the sauce splits. It reproduces on SQL Server 2025 every time, and I have the timestamps and the deadlock graph to prove it.
T-SQL Mistakes: Careless and Careful Write the Same Six Queries
T-SQL mistakes, in the two-panel format the children’s magazines used. Careless writes it one way. Careful writes it the other. Every pair was run on the same 1,200,000 rows on SQL Server 2025 and measured. One pair returned a wrong answer. One I stopped after fourteen minutes of CPU.
Slow Queries: A Field Guide to Eight Species
Slow queries, identified the way a field guide identifies birds: by silhouette, habitat, call, and the species they’re confused with. All eight were raised in the lab on SQL Server 2025. The reads and the wait types are what each one produced.
SQL Server 2025 Cheat Sheet: Every Query Tested, Free PDF
This SQL Server 2025 cheat sheet puts the T-SQL I use every day on four printable pages. Every query ran on SQL Server 2025 first, and all the scripts are in the post. It covers joins, window functions, regular expressions, JSON, indexes, backups and SSMS shortcuts.
Erdős Unit Distance Problem: What It Is and What AI Found
The Erdős unit distance problem asks how many pairs of points can sit exactly one unit apart. Paul Erdős guessed the answer in 1946, and the guess stood for eighty years. In May 2026, an OpenAI model found a counterexample. I checked the grid trick behind it in SQL Server, spatial queries included.
Outdated Statistics in SQL Server: The Optimizer Is Planning for Last Year
Outdated statistics in SQL Server can slow a query even when its code has not changed. On SQL Server 2025 with the legacy estimator, a stale statistic sent one join to 120,043 logical reads, and a targeted update brought it down to 18,220. Auto update helps, but it waits for a threshold, it samples, and it knows nothing about the rows that arrived today.