Oracle Index Pocket Reference

Consider EMP table : UID VARCHAR2(25) PRIMARY KEY, JOINING_DATE DATE, ENAME VARCHAR2(100), DESG VARCHAR2(50), JOB_CODE VARCHAR2(50))
Index Type	Indexed Columns	Result	Query
Composite Index	uid, joining_date	index works for both columns	where uid='GANESH' and joining_date between '01-jan-11' and '31-jan-11'
		index works for uid	where uid='GANESH' and trunc(joining_date) between '01-jan-11' and '31-jan-11'
		Full Table scan	where upper(uid)='GANESH' and joining_date between '01-jan-11' and '31-jan-11'
		index works for joining_date	where joining_date = '01-jan-11'
		Full Table scan	where trunc(joining_date) = '01-jan-11'
		index works for joining_date	select /*+ index(Join_dt_I1) */  * from emp  where   joining_date between  '01-jan-11' and '31-jan-11'
Bit Map	Job_Code	Full Table scan	where   trunc(joining_date) between  '01-jan-11' and '31-jan-11' and Job_Code='UUUIII23'
		index works for joining_date and r_code	where   joining_date between  '01-jan-11' and '31-jan-11' and Job_Code='UUUIII23'