Get the Execution plan from SQL ID!!!
Check the Execution plan from SQL ID!!!
High level steps
1. Get the SQL ID for the SQL Statement
2. Get the explain plain or execution plan for the SQL ID.
1. Get the SQL ID for the SQL Statement
- First you need to execute the SQL statement to get the SQL ID from v$sql view.
- You can get the SQL ID from AWR report or ASH report or you can get from the current session
SQL> set pages 1000 lines 1000
SQL> SELECT * FROM EMP;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7839 KING 17-NOV-81 5000 10
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7566 JONES MANAGER 7839 02-APR-81 2975 20
7788 SCOTT ANALYST 7566 19-APR-87 3000 20
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7369 SMITH CLERK 7902 17-DEC-80 800 20
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7876 ADAMS CLERK 7788 23-MAY-87 1100 20
7900 JAMES CLERK 7698 03-DEC-81 950 30
7934 MILLER CLERK 7782 23-JAN-82 1300 10
14 rows selected.
SQL>
SQL> select sql_id from v$sql where sql_text like 'SELECT * FROM EMP';
SQL_ID
-------------
4ttqgu8uu8fus
2. Get the explain plain or execution plan for the SQL
SQL> select sql_id from v$sql where sql_text like 'SELECT * FROM EMP';
SQL_ID
-------------
4ttqgu8uu8fus
SQL> set line 200 pages 200
SQL> SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('&sqlid'));
SQL> Enter value for sqlid: 4ttqgu8uu8fus
old 1: SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('&sqlid'))
new 1: SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('4ttqgu8uu8fus'))
PLAN_TABLE_OUTPUT
-----------------------------------------------------------------------------
SQL_ID 4ttqgu8uu8fus, child number 0
-------------------------------------
SELECT * FROM EMP
Plan hash value: 3956160932
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | | | 3 (100)| |
| 1 | TABLE ACCESS FULL| EMP | 14 | 532 | 3 (0)| 00:00:01 |
--------------------------------------------------------------------------
13 rows selected.
SQL>
Demo 2: (Best Query)
SQL> SELECT * FROM EMP where EMPNO=7839;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- --------- ---------- ---------- ----------
7839 KING PRESIDENT 17-NOV-81 5000 10
SQL> select sql_id from v$sql where sql_text like 'SELECT * FROM EMP where EMPNO=7839';
SQL_ID
-------------
dm0ndwh8c28aj
SQL> set line 200 pages 200
SQL> SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('&sqlid'));
Enter value for sqlid: dm0ndwh8c28aj
old 1: SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('&sqlid'))
new 1: SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('dm0ndwh8c28aj'))
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL_ID dm0ndwh8c28aj, child number 0
-------------------------------------
SELECT * FROM EMP where EMPNO=7839
Plan hash value: 2949544139
--------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | | | 1 (100)| |
| 1 | TABLE ACCESS BY INDEX ROWID| EMP | 1 | 38 | 1 (0)| 00:00:01 |
|* 2 | INDEX UNIQUE SCAN | PK_EMP | 1 | | 0 (0)| |
--------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
2 - access("EMPNO"=7839)
19 rows selected.
SQL>
Demo 3: (Bad Query)
SQL> set line 200 pages 200
SQL> SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('&sqlid'));
Enter value for sqlid: 071z8v8jqhyx4
old 1: SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('&sqlid'))
new 1: SELECT * FROM TABLE (DBMS_XPLAN.DISPLAY_CURSOR ('071z8v8jqhyx4'))
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL_ID 071z8v8jqhyx4, child number 0
-------------------------------------
SELECT * FROM EMP where ENAME='KING'
Plan hash value: 3956160932
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | | | 3 (100)| |
|* 1 | TABLE ACCESS FULL| EMP | 1 | 38 | 3 (0)| 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter("ENAME"='KING')
18 rows selected.
SQL>
Regards,
Mallik
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