Character string without wildcards

A LIKE predicate is transformed into a predicate that uses the = operator (and a NOT LIKE predicate is transformed into one that uses <>) when the character string does not contain any wildcards. For example:
country LIKE 'Chile'
becomes
country = 'Chile'
and
country NOT LIKE 'Chile'
becomes
country <> 'Chile'

Predicates that use the = operator are optimizable. Predicates that use the <> operator are sargable.

Related reference
Character string beginning with constant
Unknown parameter