NOT Operator Optimizations

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Starting with InterBase 2020 conditions using NOT operators have been optimized, a condition like NOT A>0 can be transformed to A<=0 so an index on column A can be used. All inequality operators <, <=, !=, <>, >, >= can also be transformed and optimized. Additionally, all NOT conditions can be transformed recursively when possible.

For example:

F1 NOT BETWEEN val1 AND val2

Transforms to:

F1 < val1 OR F1 > val2

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