Suppose a table contain a same name with different case. How to retervie that all records from table. I hope u understand the question.
SELECT name FROM foo WHERE UPPER(name) = UPPER('dEvAnG')
would find all 3 using a tablescan.
INSERT INTO foo(name, allUpper) VALUES ('dEvAnG', UPPER('dEvAnG'))
SELECT name FROM foo WHERE allUpper = UPPER('dEvAnG')may use an index on allUpper improving performance at the cost of storing the data twice.
-- Jeremy
