ORed search has the form
, as in this
WHERE column1 = 'x' OR column2 = 'y'
Here the optimizer's decision is to use a sequential scan.
The above warning does not apply if the same column is used in both conditions. For example:
WHERE column1 = 'x' OR column1 = 'y'
In such a case, the search is indexed because the expression
is a range search. This subject will be revisited during the
discussion of the