Hi sir,
can you please guide me the process of index works,in the below is one scenario
as
CREATE TABLE DEPT(deptid NUMBER(4) PRIMARY KEY, deptname CHAR(10));
CREATE INDEX dept_deptname_idx ON DEPT(deptname);
/* The DEPT table contains 10,000 rows and the .deptname column contains 10 unique values that are evenly distributed. */
Based on the scenario above, which query needs to use the dept_deptname_idx index?
SELECT deptid FROM DEPT WHERE deptid 1234;
SELECT deptid FROM DEPT WHERE deptname = ‘SALES’;
SELECT DISTINCT deptid FROM DEPT;
SELECT deptid FROM DEPT WHERE deptname ‘SALES’;
SELECT deptid FROM DEPT WHERE deptid < 1234;
please answer it and give me the how and why is pocessing
regard