CREATE INDEX ename1_idx ON emp1(ename);
CREATE INDEX ename2_idx ON emp2(ename);
CREATE INDEX ename3_idx ON emp3(ename);
CREATE INDEX ename4_idx ON emp4(ename);

--DROP INDEX ename1_idx;
--DROP INDEX ename2_idx;
--DROP INDEX ename3_idx;
--DROP INDEX ename4_idx;

CREATE INDEX sal_ename1_idx ON emp1(sal, ename);
CREATE INDEX sal_ename2_idx ON emp2(sal, ename);
CREATE INDEX sal_ename3_idx ON emp3(sal, ename);
CREATE INDEX sal_ename4_idx ON emp4(sal, ename);

--DROP INDEX sal_ename1_idx;
--DROP INDEX sal_ename2_idx;
--DROP INDEX sal_ename3_idx;
--DROP INDEX sal_ename4_idx;

CREATE INDEX ename1_hiredate_idx ON emp1(ename, hiredate);
CREATE INDEX ename2_hiredate_idx ON emp2(ename, hiredate);
CREATE INDEX ename3_hiredate_idx ON emp3(ename, hiredate);
CREATE INDEX ename4_hiredate_idx ON emp4(ename, hiredate);

--DROP INDEX ename1_hiredate_idx;
--DROP INDEX ename2_hiredate_idx;
--DROP INDEX ename3_hiredate_idx;
--DROP INDEX ename4_hiredate_idx;

CREATE INDEX hiredate_sal_ename1_idx ON emp1(hiredate, sal, ename);
CREATE INDEX hiredate_sal_ename2_idx ON emp2(hiredate, sal, ename);
CREATE INDEX hiredate_sal_ename3_idx ON emp3(hiredate, sal, ename);
CREATE INDEX hiredate_sal_ename4_idx ON emp4(hiredate, sal, ename);

--DROP INDEX hiredate_sal_ename1_idx;
--DROP INDEX hiredate_sal_ename2_idx;
--DROP INDEX hiredate_sal_ename3_idx;
--DROP INDEX hiredate_sal_ename4_idx;
