• Yep. It's cumulative, so a plan with zero value ads zero to the number. Understand though, just because an operator says it has zero cost doesn't mean it actually did zero work. It just means that the optimizer didn't assign it a cost.

    Also remember, these are all fake numbers, just estimates, even on an actual plan. They are meaningful within a given plan, but you can't use them to compare one plan to another really. Instead you need to rely on query execution time and I/O costs.

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    Author of:
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