Range conditions are search conditions with a comparison predicate or a BETWEEN predicate, to which the following prerequisites apply:
· The only valid operators are the relational operators < | <= | => | > and the operator BETWEEN.
·
Range
conditions have one of the following formats:
<column_spec> <
< | <= | => | >
> <extended_value_spec>
<column_spec> BETWEEN <extended_value_spec> AND
<extended_value_spec>
The Optimizer can only use range conditions that satisfy these prerequisites to determine an optimal search strategy.
Whether the range is defined using a BETWEEN operator or using a combination of the relational operators <= and => is irrelevant to the search strategy.
Conditions in the format ...NOT (<column_spec> < < | <= | => | > > <extended_value_spec>) or. ...NOT (<column_spec> NOT BETWEEN <extended_value_spec> AND <extended_value_spec>)are, where possible, converted to an expression without NOT, with a correspondingly negated operator. The system then continues processing the condition in this converted format.