--R1
explain plan
SET statement_id ='R1'
FOR
SELECT COUNT(*) FROM SALARIES
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R1'
ORDER BY id;

DELETE FROM plan_table;

--R2
CREATE INDEX idxIdSalarieSalarie ON salaries (idSalarie);

explain plan
SET statement_id ='R2'
FOR
SELECT COUNT(*) FROM SALARIES
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R2'
ORDER BY id;

DELETE FROM plan_table;


DROP INDEX idxIdSalarieSalarie;


--R3
ALTER TABLE salaries ADD CONSTRAINT pkSalarieIdSalarie PRIMARY
KEY (idSalarie);

explain plan
SET statement_id ='R3'
FOR
SELECT COUNT(*) FROM SALARIES
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R3'
ORDER BY id;

DELETE FROM plan_table;

--R4

ALTER SESSION SET OPTIMIZER_MODE = RULE;

explain plan
SET statement_id ='R4'
FOR
SELECT COUNT(*) FROM SALARIES
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R4'
ORDER BY id;

DELETE FROM plan_table;

--R5
ALTER SESSION SET OPTIMIZER_MODE = ALL_ROWS;

explain plan
SET statement_id ='R5'
FOR
SELECT * FROM SALARIES
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R5'
ORDER BY id;

DELETE FROM plan_table;


--R6
explain plan
SET statement_id ='R6'
FOR
SELECT * FROM SALARIES
WHERE IDSALARIE=5000;
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R6'
ORDER BY id;

DELETE FROM plan_table;


--R7
CREATE INDEX idxEnameSalaries ON salaries (ename);

explain plan
SET statement_id ='R7'
FOR
SELECT * FROM SALARIES
WHERE ename='SCOTT';
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R7'
ORDER BY id;

DELETE FROM plan_table;

--R8
CREATE INDEX idxEnameSalaries ON salaries (ename);

ALTER SESSION SET OPTIMIZER_MODE = FIRST_ROWS;
explain plan
SET statement_id ='R8'
FOR
SELECT * FROM SALARIES
WHERE ename='SCOTT';
COMMIT;


SELECT operation,options,id,parent_id,object_name
FROM PLAN_TABLE
WHERE statement_id = 'R8'
ORDER BY id;

DELETE FROM plan_table;