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< The problem of finding **overlapping** ranges in table(id,low,upper) looks trivial. I tried to find elegant solution, so I decided to describe non-overlapping set and then invert logical expression.

**to**

> The problem of finding **overlaped** ranges in table(id,low,upper) looks trivial. I tried to find elegant solution, so I decided to describe non-overlapping set and then invert logical expression.

## Finding overlapping ranges

The problem of finding overlaped ranges in table(id,low,upper) looks trivial. I tried to find elegant solution, so I decided to describe non-overlapping set and then invert logical expression.

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NOT(t1.low >= t2.upper or t1.upper <= t2.low)

Then I want to exclude equal ranges

NOT(t1.low >= t2.upper or t1.upper <= t2.low or (t1.low = t2.low and t1.upper = t2.upper )

We don't want to do extra matches, so

NOT(t1.low >= t2.upper or t1.upper <= t2.low or (t1.low = t2.low and t1.upper = t2.upper ) and t1.id > t2.id