# Character string beginning with constant

A LIKE predicate in which a column is compared to a character string that begins with a character constant (not a wildcard) is transformed into three predicates: one predicate that uses the LIKE operator, one that uses the `>=` operator, and one that uses the `<` operator.

For example,

    country LIKE 'Ch%i%'

becomes

    country LIKE 'Ch%i%'
    AND country >= 'Ch'
    AND country < 'Ci'

The first (LIKE) predicate is not optimizable, but the new predicates added by the transformation are.

When the character string begins with one more character constants and ends with a single "%", the first LIKE clause is eliminated. For example,

    country LIKE 'Ch%'

becomes

    country >= 'Ch'
    AND country < 'Ci'

Parent topic: LIKE transformations
Related reference
Character string without wildcards
Unknown parameter