Development

Why Are Linked Server Queries So Bad?

Development
79 Comments
No, I don’t want to be your valentine. Remember when you were in school, and you had a crush on someone? You would write a note asking them to be your valentine, and you’d ask a mutual friend to pass the note over to them. The adult equivalent is linked server queries. When your query…
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What does SET NOCOUNT ON do?

T-SQL
13 Comments
When you’re working with T-SQL, you’ll often see SET NOCOUNT ON at the beginning of stored procedures and triggers. What SET NCOUNT ON does is prevent the “1 row affected” messages from being returned for every operation. I’ll demo it by writing a stored procedure in the Stack Overflow database to cast a vote: CREATE…
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Brent Reading Book

9 Signs Your T-SQL Might Fail a Code Review

T-SQL
25 Comments
It’s hard to set absolute rules about, “Feature X should absolutely never be used.” However, there are some features that set off alarm bells when I see them. Usually, when I start asking more questions about when we’re using those particular features, I get answers of, “Oh, I didn’t know that was a problem.” As…
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4 Things I Love About Integers #TSQL2sday

Development
4 Comments
I love integers. Furthermore, I think we’ve all been taking them for granted. Integers are clean, elegant datatypes that do exactly what they’re supposed to. They’re the Golden Retrievers of the database world: they have a few shortcomings, but so, so few. And so for this month’s T-SQL Tuesday, I wanna share my love for…
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“But Surely NOLOCK Is Okay If No One’s Changing Data, Right?”

Some of y’all, bless your hearts, are really, really, really in love with NOLOCK. I’ve shown you how you get incorrect results when someone’s updating the rows, and I’ve shown how you get wrong-o results when someone’s updating unrelated rows. It doesn’t matter – there’s always one of you out there who believes NOLOCK is okay…
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How to Batch Updates A Few Thousand Rows at a Time

T-SQL
15 Comments
You’ve got a staging table with millions of rows, and you want to join that over to a production table and update the contents. However, when you try to do it all in one big statement, you end up with lock escalation, large transaction log usage, slow replication to Availability Groups, and angry users with…
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