NOT Operator Optimizations
From InterBase
Go Up to Understanding SQL Expressions
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