Contrasting Common Table Expressions and Temp Tables

Brent Ozar has some advice on when to use common table expressions versus temporary tables:

I’d suggest starting with CTEs because they’re easy to write and to read. If you hit a performance wall, try ripping out a CTE and writing it to a temp table, then joining to the temp table.

This is my advice, too. Start with the thing which is easiest for you to develop and maintain. If it suffices for performance, stick with it; otherwise, move to the next-lowest level of complication. Stop when you have good enough performance. This optimizes for one of the most precious resources people rarely think about: developer maintenance time. Developers are pretty expensive, so the more time they spend trying to understand complex code, the less time they’re doing stuff which pushes the business forward.

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