Query Exercise Answers: Why Are These 3 Estimates So Wrong?
This week’s Query Exercise challenged you to figure out why these 3 estimates went so badly: SELECT TOP […]
Query Exercise Answers
Query Exercise Answer: What Makes SELECT TOP 1 or SELECT ...
This Query Exercise was very different: I didn’t ask you to solve a particular problem. I pointed out […]
Query Exercise Answer: Fixing a Slow Computed Column
In last week’s Query Exercise, we added a user-defined function to the Users table to check whether their […]
Query Exercise Answer: Beating ChatGPT at Finding Good Question Times
For this week’s Query Exercise, I asked you to write a better query than ChatGPT wrote. Your goal […]
Getting Data Out of an Audit Table: Answers & Discussion
In last week’s post, I gave you a trigger that populated a history table with all changes to […]
Who’s Changing the Table? Answers and Discussion
Your challenge for this week was to find out who keeps mangling the contents of the AboutMe column […]
Finding Sister Locations to Help Each Other: Answers & Discussion
This week’s query exercise asked you to find two kinds of locations in the Stack Overflow database: Locations […]
Find Recent Superstars: Answers & Discussion
Your query exercise for this week was to write a query to find users created in the last […]
Finding Long Values Faster: Answers & Discussion
In last week’s Query Exercise, our developers had a query that wasn’t going as fast as they’d like: […]
Improving Cardinality Estimation: Answers & Discussion
Your challenge for last week was to take this Stack Overflow database query to show the top-ranking users […]
Database Changes to Find Tagged Questions Faster: Answers and Discussion
In the last Query Exercise discussion, we hit a performance wall when we were trying to quickly find […]
Finding Tagged Questions Faster: Answers & Discussion
Your query exercise was to take this Stack Overflow query to find the top-voted questions for any given […]
Finding the Best Time for Maintenance: Answers & Discussion
Your Query Exercise was to find the best time to do database maintenance by querying the Users table, […]
Find Posts with the Wrong CommentCount: Answers & Discussion
Your Query Exercise was to find denormalization accuracy problems: checking the accuracy of a reporting column, Posts.CommentCount. There […]