提高pl / sql的性能，想在Q1的结果上执行Q2

CREATE or REPLACE PROCEDURE TEST(
activationStartDate IN DATE,
activationEndDate IN DATE,
deActivationStartDate IN DATE,
deActivationEndDate IN DATE
)
AS
FirstNameListTable LIST_TABLE;

{--COMMENT :LIST_TABLE is nested table :create or replace TYPE "LIST_TABLE" as table     of varchar2(20);-----Nested Table Declaration
/
}

totalSameFirstName NUMBER;
j NUMBER := 1;
BEGIN



SELECT first_name BULK COLLECT INTO FirstNameListTable FROM Employee where start_date between activationStartDate AND activationEndDate 
MINUS 
SELECT first_name FROM Employee where start_date between deActivationStartDate AND deActivationEndDate


FOR i IN FirstNameListTable.FIRST .. FirstNameListTable.LAST LOOP
     SELECT count(*) INTO totalSameFirstName FROM Employee where start_date between activationStartDate AND activationEndDate AND first_name=FirstNameListTable(i)

       IF totalSameFirstName > 2 THEN
            ---business logic
       END IF;
END LOOP;
CREATE or REPLACE PROCEDURE TEST(
activationSta