AUTOTRACE table joining and aggregate function : autotrace « SQL PLUS Session Environment « Oracle PL/SQL Tutorial

1. Oracle PL/SQL Tutorial
2. SQL PLUS Session Environment
3. autotrace

SQL>CREATE TABLE project (
  2    pro_id              NUMBER(4),
  3    pro_name            VARCHAR2(40),
  4    budget          NUMBER(9,2),
  5    CONSTRAINT project_pk   PRIMARY KEY (pro_id)
  6  );

Table created.

SQL>
SQL>
SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1001, 'A',12345);

1 row created.

SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1002, 'ERP',23456);

1 row created.

SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1003, 'SQL',34567);

1 row created.

SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1004, 'CRM',45678);

1 row created.

SQL>INSERT INTO project(pro_id, pro_name, budget)VALUES (1005, 'VPN',56789);

1 row created.

SQL>
SQL>
SQL>CREATE TABLE server_usage (
  2    pro_id                   NUMBER(4),
  3    emp_id                  NUMBER,
  4    time_log_date                DATE,
  5    hours_logged                 NUMBER(8,2),
  6    dollars_charged              NUMBER(8,2),
  7    CONSTRAINT server_usage_pk  PRIMARY KEY (pro_id, emp_id, time_log_date)
  8  );

Table created.

SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
  2                    VALUES (1001,101,to_date('4-Apr-2004','dd-mon-yyyy'),1123,222);

1 row created.

SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
  2                    VALUES (1002,102,to_date('4-Apr-2005','dd-mon-yyyy'),1124,223);

1 row created.

SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
  2                    VALUES (1003,103,to_date('4-Apr-2006','dd-mon-yyyy'),1125,224);

1 row created.

SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
  2                    VALUES (1004,104,to_date('4-Apr-2007','dd-mon-yyyy'),1126,225);

1 row created.

SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
  2                    VALUES (1005,105,to_date('4-Apr-2008','dd-mon-yyyy'),1127,226);

1 row created.

SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
  2                    VALUES (1001,106,to_date('4-Apr-2009','dd-mon-yyyy'),1128,227);

1 row created.

SQL>INSERT INTO server_usage(pro_id, emp_id, time_log_date, hours_logged, dollars_charged)
  2                    VALUES (1002,107,to_date('4-Apr-2010','dd-mon-yyyy'),1129,228);

1 row created.

SQL>
SQL>CREATE TABLE emp (
  2    emp_id               NUMBER,
  3    ename             VARCHAR2(40),
  4    hire_date        DATE DEFAULT sysdate,
  5    end_date DATE,
  6    rate     NUMBER(5,2),
  7    CONSTRAINT emp_pk    PRIMARY KEY (emp_id)
  8  );

Table created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (101, 'Mary', to_date('15-Nov-1961','dd-mon-yyyy'),null,169);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (102, 'Tom', to_date('16-Sep-1964','dd-mon-yyyy'),to_date('5-May-2004','dd-mon-yyyy'),135);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (104, 'Peter', to_date('29-Dec-1987','dd-mon-yyyy'),to_date('1-Apr-2004','dd-mon-yyyy'),99);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (105, 'Mike', to_date('15-Jun-2004','dd-mon-yyyy'),null,121);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (107, 'Less', to_date('2-Jan-2004','dd-mon-yyyy'),null,45);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (108, 'Park', to_date('1-Mar-1994','dd-mon-yyyy'),to_date('15-Nov-2004','dd-mon-yyyy'),220);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (110, 'Ink', to_date('4-Apr-2004','dd-mon-yyyy'),to_date('30-Sep-2004','dd-mon-yyyy'),84);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (111, 'Tike', to_date('23-Aug-1976','dd-mon-yyyy'),null,100);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (112, 'Inn', to_date('15-Nov-1961','dd-mon-yyyy'),to_date('4-Apr-2004','dd-mon-yyyy'),70);

1 row created.

SQL>INSERT INTO emp(emp_id, ename, hire_date,end_date, rate)VALUES (113, 'Kate', to_date('3-Mar-2004','dd-mon-yyyy'),to_date('31-Oct-2004','dd-mon-yyyy'),300);

1 row created.

SQL>
SQL>
SQL>SET ECHO ON
SQL>SET AUTOTRACE ON EXPLAIN
SQL>
SQL>SELECT ename, SUM(hours_logged)
  2  FROM emp, server_usage
  3  WHERE emp.emp_id = server_usage.emp_id
  4  GROUP BY ename;

User System Privileges                                              Page    1

                     SUM(HOURS_LOGGED)
-------------------- -----------------
Less                              1129
Mary                              1123
Mike                              1127
Peter                             1126
Tom                               1124

5 rows selected.


Execution Plan
----------------------------------------------------------
Plan hash value: 2561811960

------------------------------------------------------
| Id  | Operation                     | Name         |
------------------------------------------------------
|   0 | SELECT STATEMENT              |              |
|   1 |  SORT GROUP BY                |              |
|   2 |   NESTED LOOPS                |              |
|   3 |    TABLE ACCESS FULL          | SERVER_USAGE |
|   4 |    TABLE ACCESS BY INDEX ROWID| EMP          |
|*  5 |     INDEX UNIQUE SCAN         | EMP_PK       |
------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   5 - access("EMP"."EMP_ID"="SERVER_USAGE"."EMP_ID")

Note
-----
   - rule based optimizer used (consider using cbo)

SQL>
SQL>set autotrace off
SQL>
SQL>drop table emp;

Table dropped.

SQL>drop table project;

Table dropped.

SQL>drop table server_usage;

Table dropped.