SQL Server

Where Clustered Index Keys Dare

Colonel Clustered We’ve blogged a couple times about how clustered index key columns get stored in your nonclustered indexes: here and here. But where they get stored is a matter of weird SQL trivia. You see, it depends on how you define your nonclustered index. “It Depends” We all scream for dependencies! Hooray! If you…
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When Query Plans Lie Part 2

Getting Weirder In Part 1, we looked at how query plans can tell us little lies. Now we’re going to look at how those little lies can turn into bigger lies. Adding An Index Right now, this is our query: Transact-SQL SELECT u.UpVotes, u.DownVotes FROM dbo.Users AS u WHERE u.Reputation >= 100000; 123 SELECT u.UpVotes,…
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Parameter Fluid Optimization

Optimizer Studies I don’t have a real job, which means that if something strikes my fancy, like staring at a spot on the wall for an hour, I can do it. Occasionally things are a bit more inspired, and so I go poking around what SMRT PPL might be up to. All you nice people…
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So You Wanna Debug SQL Server Part 2

Birth Control Debugging, and, heck, even learning about debugging, is a time-consuming and often unhelpful process when it comes to tracking down issues in SQL Server. It is arduous and tedious, and yields little chance of making you any friends. So why write about it? Mostly because no one else is willing to — at…
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Azure SQL DB Managed Instances: We’re All GUIDs

Six is having problems adjusting to his clone status Some funny things happen when you create databases up in a Managed Instance. For Instance (HEH!), you may expect this to yield some fruitful results, but it Manages (HAH!) to defy logic. Transact-SQL CREATE DATABASE YourMom; SELECT * FROM sys.master_files WHERE name = 'YourMom'; 12345 CREATE DATABASE YourMom; SELECT…
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