CREATE TABLE T
  (C1 NUMBER(15),C2 VARCHAR2(100)
  );
---loop to insert data
DECLARE
  I NUMBER:=1;
BEGIN
  LOOP
    INSERT INTO T VALUES
      (I,'HERE IS THE TEST FOR INDEX TIMING'
      );
    EXIT
  WHEN I > 100000;
    I   :=I+1;
  END LOOP;
END;     --INSERT TIME IS 17.66282082

SELECT * FROM T WHERE C2 LIKE '%T%';--BRINING PAGES INTO MAIN MEMORY 0.79051524
SELECT * FROM T WHERE C2 LIKE '%T%';--2ND TIME 0.05776433
SELECT * FROM T WHERE C2 LIKE '%T%';--3RD TIME 0.013183603 <<<
SELECT * FROM T WHERE C2 LIKE '%T%';--4TH TIME 0.15524571  <<<
SELECT * FROM T WHERE C2 LIKE '%T%';--4TH TIME 0.01455576  <<<

--cREATING INDEXES
CREATE INDEX INDEXONC1 ON T
  (C1,C2
  );--6.02679539

--NOW REINSERT DATA INTO
DECLARE
  I NUMBER:=100001;
BEGIN
  LOOP
    INSERT INTO T VALUES
      (I,'HERE IS THE TEST FOR INDEX TIMING'
      );
    EXIT
  WHEN I > 200000;
    I   :=I+1;
  END LOOP;
END;--INSERT TIME IS [B]61.04084778[/B](17.66282082) <<<
----