guy.stephens (10/27/2013)
Much as we love the Merge statement in my workplace, we seem to be running into deadlocking problems that we haven't had when using the UPDATE/INSERT .. LEFT JOIN approach.We haven't investigated too deeply but are tending back to UPDATE/INSERT on large datasets. Would be glad to hear from anyone else who has experienced this.
I personally have not experienced this issue, however with a 28% performance hit it wouldn't surprise me.
I would say that if you are really expecting to INSERT/UPDATE 100s of 1000s of rows, it might be a good idea to stick to the traditional.
I guess the key words here are "it depends."
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
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Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
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