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Azure Database Support Blog
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Lesson Learned #531: Scalar UDF vs Parallelism

Jose_Manuel_Jurado's avatar
Jul 31, 2025

Last week I worked on a support case where our customer reported that the exact same query, executed against two identical databases with the same resources, was taking significantly longer on one of them. Both databases had the same number of rows, up-to-date statistics, and identical indexes. We started by collecting the execution plans, and I’d like to share what we found.

Last week I worked on a support case where our customer reported that the exact same query, executed against two identical databases with the same resources, was taking significantly longer on one of...
Published Jul 31, 2025
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