Comparing Nullable Columns

Daniel Hutmacher shows an elegant way to compare multiple nullable columns on two tables:

Because we’ve added OR conditions into the mix, we’re forced to use the Nested Loop join, which loops over table B for every single row in A. That’s a lot of index scans and it comes with a hefty price tag.

Here’s an absolutely eye-watering beautiful pattern that I found on the Interwebs (though I forgot where) the other day.

This is an interesting use of INTERSECT.  Check it out.

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Bugs and Pitfalls with Non-Determinism

Itzik Ben-Gan has started a new series on T-SQL bugs, pitfalls, and best practices. The first post in this series is on non-deterministic behavior: A nondeterministic function is a function that given the same inputs, can return different results in different executions of the function. Classic examples are SYSDATETIME, NEWID, and RAND (when invoked without […]

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Changing Constraints in Near-Zero Downtime Situations

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