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This article was originally published on 𝕏. I was asked recently why Halloween Protection was needed for data modification statements tha...

This article was originally published on 𝕏. Introduction Update execution plans are not something the T-SQL statement writer has much co...

A bug with Halloween Protection and the OUTPUT Clause Background The OUTPUT clause can be used to return results fro...

Halloween Protection – The Complete Series I have written a four-part series on the Halloween Problem . Some of you wi...

The Halloween Problem – Part 4 The Halloween Problem can have a number of important effects on execution plans. In this...

The Halloween Problem – Part 3 The MERGE statement (introduced in SQL Server 2008) allows us to perform a mixture of ...

The Halloween Problem – Part 2 In the first part of this series , we saw how the Halloween Problem applies to UPDATE q...

The Halloween Problem – Part 1 Much has been written over the years about understanding and optimizing SELECT queries,...

Optimizing T-SQL queries that change data Most tuning efforts for data-changing operations concentrate on the SELECT s...

Deletes that Split Pages and Forwarded Ghosts Can DELETE operations cause pages to split? Yes. It sounds counter-int...

The Impact of Non-Updating Updates From time to time, I encounter a system design that always issues an UPDATE against...