1.explain plan
scott@ORCLPDB01 2023-04-02 19:49:41> explain plan for select empno,ename,dname from emp,dept where emp.deptno = dept.deptno;
Explained.
Elapsed: 00:00:00.01
scott@ORCLPDB01 2023-04-02 19:50:51> select * from table(dbms_xplan.display);
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 844388907
----------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 364 | 6 (17)| 00:00:01 |
| 1 | MERGE JOIN | | 14 | 364 | 6 (17)| 00:00:01 |
| 2 | TABLE ACCESS BY INDEX ROWID| DEPT | 4 | 52 | 2 (0)| 00:00:01 |
| 3 | INDEX FULL SCAN | PK_DEPT | 4 | | 1 (0)| 00:00:01 |
|* 4 | SORT JOIN | | 14 | 182 | 4 (25)| 00:00:01 |
| 5 | TABLE ACCESS FULL | EMP | 14 | 182 | 3 (0)| 00:00:01 |
----------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
4 - access("EMP"."DEPTNO"="DEPT"."DEPTNO")
filter("EMP"."DEPTNO"="DEPT"."DEPTNO")
18 rows selected.
Elapsed: 00:00:00.032.dbms_xplan
2.1.
scott@ORCLPDB01 2023-04-02 19:49:41> explain plan for select empno,ename,dname from emp,dept where emp.deptno = dept.deptno;
Explained.
Elapsed: 00:00:00.01
scott@ORCLPDB01 2023-04-02 19:50:51> select * from table(dbms_xplan.display);
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 844388907
----------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 364 | 6 (17)| 00:00:01 |
| 1 | MERGE JOIN | | 14 | 364 | 6 (17)| 00:00:01 |
| 2 | TABLE ACCESS BY INDEX ROWID| DEPT | 4 | 52 | 2 (0)| 00:00:01 |
| 3 | INDEX FULL SCAN | PK_DEPT | 4 | | 1 (0)| 00:00:01 |
|* 4 | SORT JOIN | | 14 | 182 | 4 (25)| 00:00:01 |
| 5 | TABLE ACCESS FULL | EMP | 14 | 182 | 3 (0)| 00:00:01 |
----------------------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
4 - access("EMP"."DEPTNO"="DEPT"."DEPTNO")
filter("EMP"."DEPTNO"="DEPT"."DEPTNO")
18 rows selected.
Elapsed: 00:00:00.032.2.
scott@ORCLPDB01 2023-04-02 19:51:18> select empno,ename,dname from emp,dept where emp.deptno = dept.deptno;
EMPNO ENAME DNAME
---------- ---------- --------------
7782 CLARK ACCOUNTING
7839 KING ACCOUNTING
7934 MILLER ACCOUNTING
7566 JONES RESEARCH
7902 FORD RESEARCH
7876 ADAMS RESEARCH
7369 SMITH RESEARCH
7788 SCOTT RESEARCH
7521 WARD SALES
7844 TURNER SALES
7499 ALLEN SALES
7900 JAMES SALES
7698 BLAKE SALES
7654 MARTIN SALES
14 rows selected.
Elapsed: 00:00:00.00
scott@ORCLPDB01 2023-04-02 19:54:29> select * from table(dbms_xplan.display(null,null,'advanced'));
PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Plan hash value: 844388907
----------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 14 | 364 | 6 (17)| 00:00:01 |
| 1 | MERGE JOIN | | 14 | 364 | 6 (17)| 00:00:01 |
| 2 | TABLE ACCESS BY INDEX ROWID| DEPT | 4 | 52 | 2 (0)| 00:00:01 |
| 3 | INDEX FULL SCAN | PK_DEPT | 4 | | 1 (0)| 00:00:01 |
|* 4 | SORT JOIN | | 14 | 182 | 4 (25)| 00:00:01 |
| 5 | TABLE ACCESS FULL | EMP | 14 | 182 | 3 (0)| 00:00:01 |
----------------------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - SEL$1
2 - SEL$1 / DEPT@SEL$1
3 - SEL$1 / DEPT@SEL$1
5 - SEL$1 / EMP@SEL$1
Outline Data
-------------
/*+
BEGIN_OUTLINE_DATA
USE_MERGE(@"SEL$1" "EMP"@"SEL$1")
LEADING(@"SEL$1" "DEPT"@"SEL$1" "EMP"@"SEL$1")
FULL(@"SEL$1" "EMP"@"SEL$1")
INDEX(@"SEL$1" "DEPT"@"SEL$1" ("DEPT"."DEPTNO"))
OUTLINE_LEAF(@"SEL$1")
ALL_ROWS
DB_VERSION('19.1.0')
OPTIMIZER_FEATURES_ENABLE('19.1.0')
IGNORE_OPTIM_EMBEDDED_HINTS
END_OUTLINE_DATA
*/
Predicate Information (identified by operation id):
---------------------------------------------------
4 - access("EMP"."DEPTNO"="DEPT"."DEPTNO")
filter("EMP"."DEPTNO"="DEPT"."DEPTNO")
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - (#keys=0) "DNAME"[VARCHAR2,14], "EMPNO"[NUMBER,22], "ENAME"[VARCHAR2,10]
2 - "DEPT"."DEPTNO"[NUMBER,22], "DNAME"[VARCHAR2,14]
3 - "DEPT".ROWID[ROWID,10], "DEPT"."DEPTNO"[NUMBER,22]
4 - (#keys=1) "EMP"."DEPTNO"[NUMBER,22], "EMPNO"[NUMBER,22],
"ENAME"[VARCHAR2,10]
5 - "EMPNO"[NUMBER,22], "ENAME"[VARCHAR2,10], "EMP"."DEPTNO"[NUMBER,22]
Query Block Registry:
---------------------
<q o="2" f="y"><n><![CDATA[SEL$1]]></n><f><h><t><![CDATA[DEPT]]></t><s><![CDATA[
SEL$1]]></s></h><h><t><![CDATA[EMP]]></t><s><![CDATA[SEL$1]]></s></h></f></q>
60 rows selected.2.3.
sys@ORCL 2023-04-02 19:57:39> col SQL_TEXT for a60;
sys@ORCL 2023-04-02 19:57:52> select sql_text,sql_id,hash_value,child_number from v$sql where sql_text like 'select empno,ename%'
SQL_TEXT SQL_ID HASH_VALUE CHILD_NUMBER
--------------------------------------------------------------------- ------------- ---------- ------------
select empno,ename,dname from emp,dept where emp.deptno = dept.deptno 7fnnxpj6prnu0 1297863488 0
Elapsed: 00:00:00.01
sys@ORCL 2023-04-02 19:57:53> select * from table(dbms_xplan.display_cursor('7fnnxpj6prnu0',0,'advanced'));
PLAN_TABLE_OUTPUT SQL_ID
---------------------------------------------------------------------------------
select empno,ename,dname from emp,dept where emp.deptno = dept.deptno
Plan hash value: 844388907
----------------------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
----------------------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | | | 6 (100)| |
| 1 | MERGE JOIN | | 14 | 364 | 6 (17)| 00:00:01 |
| 2 | TABLE ACCESS BY INDEX ROWID| DEPT | 4 | 52 | 2 (0)| 00:00:01 |
| 3 | INDEX FULL SCAN | PK_DEPT | 4 | | 1 (0)| 00:00:01 |
|* 4 | SORT JOIN | | 14 | 182 | 4 (25)| 00:00:01 |
| 5 | TABLE ACCESS FULL | EMP | 14 | 182 | 3 (0)| 00:00:01 |
----------------------------------------------------------------------------------------
Query Block Name / Object Alias (identified by operation id):
-------------------------------------------------------------
1 - SEL$1
2 - SEL$1 / DEPT@SEL$1
3 - SEL$1 / DEPT@SEL$1
5 - SEL$1 / EMP@SEL$1
Outline Data
-------------
/*+
BEGIN_OUTLINE_DATA
IGNORE_OPTIM_EMBEDDED_HINTS
OPTIMIZER_FEATURES_ENABLE('19.1.0')
DB_VERSION('19.1.0')
ALL_ROWS
OUTLINE_LEAF(@"SEL$1")
INDEX(@"SEL$1" "DEPT"@"SEL$1" ("DEPT"."DEPTNO"))
FULL(@"SEL$1" "EMP"@"SEL$1")
LEADING(@"SEL$1" "DEPT"@"SEL$1" "EMP"@"SEL$1")
USE_MERGE(@"SEL$1" "EMP"@"SEL$1")
END_OUTLINE_DATA
*/
Predicate Information (identified by operation id):
---------------------------------------------------
4 - access("EMP"."DEPTNO"="DEPT"."DEPTNO")
filter("EMP"."DEPTNO"="DEPT"."DEPTNO")
Column Projection Information (identified by operation id):
-----------------------------------------------------------
1 - "DNAME"[VARCHAR2,14], "EMPNO"[NUMBER,22], "ENAME"[VARCHAR2,10]
2 - "DEPT"."DEPTNO"[NUMBER,22], "DNAME"[VARCHAR2,14]
3 - "DEPT".ROWID[ROWID,10], "DEPT"."DEPTNO"[NUMBER,22]
4 - (#keys=1) "EMP"."DEPTNO"[NUMBER,22], "EMPNO"[NUMBER,22],
"ENAME"[VARCHAR2,10]
5 - "EMPNO"[NUMBER,22], "ENAME"[VARCHAR2,10], "EMP"."DEPTNO"[NUMBER,22]
Query Block Registry:
---------------------
<q o="2" f="y"><n><![CDATA[SEL$1]]></n><f><h><t><![CDATA[DEPT]]></t><s><![CDATA[
SEL$1]]></s></h><h><t><![CDATA[EMP]]></t><s><![CDATA[SEL$1]]></s></h></f></q>
65 rows selected.
Elapsed: 00:00:00.172.4.
scott@ORCLPDB01 2023-04-02 20:12:33> select count(*) from t1;
COUNT(*)
----------
3
Elapsed: 00:00:00.00
scott@ORCLPDB01 2023-04-02 20:12:49> conn / as sysdba
Connected.
sys@ORCL 2023-04-02 20:12:58> select sql_text,sql_id,version_count,executions from v$sqlarea where sql_text like 'select count(*) from t1%';
SQL_TEXT
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
SQL_ID VERSION_COUNT EXECUTIONS
------------- ------------- ----------
select count(*) from t1
5bc0v4my7dvr5 1 1
Elapsed: 00:00:00.02
sys@ORCL 2023-04-02 20:13:00> col SQL_TEXT for a45;
sys@ORCL 2023-04-02 20:13:12> r
1* select sql_text,sql_id,version_count,executions from v$sqlarea where sql_text like 'select count(*) from t1%'
SQL_TEXT SQL_ID VERSION_COUNT EXECUTIONS
--------------------------------------------- ------------- ------------- ----------
select count(*) from t1 5bc0v4my7dvr5 1 1
Elapsed: 00:00:00.02sys@ORCLPDB01 2023-04-02 20:35:30> select * from scott.emp;
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
---------- ---------- --------- ---------- ------------------- ---------- ---------- ----------
7369 SMITH CLERK 7902 1980-12-17 00:00:00 800 20
7499 ALLEN SALESMAN 7698 1981-02-20 00:00:00 1600 300 30
7521 WARD SALESMAN 7698 1981-02-22 00:00:00 1250 500 30
7566 JONES MANAGER 7839 1981-04-02 00:00:00 2975 20
7654 MARTIN SALESMAN 7698 1981-09-28 00:00:00 1250 1400 30
7698 BLAKE MANAGER 7839 1981-05-01 00:00:00 2850 30
7782 CLARK MANAGER 7839 1981-06-09 00:00:00 2450 10
7788 SCOTT ANALYST 7566 1987-04-19 00:00:00 3000 20
7839 KING PRESIDENT 1981-11-17 00:00:00 5000 10
7844 TURNER SALESMAN 7698 1981-09-08 00:00:00 1500 0 30
7876 ADAMS CLERK 7788 1987-05-23 00:00:00 1100 20
7900 JAMES CLERK 7698 1981-12-03 00:00:00 950 30
7902 FORD ANALYST 7566 1981-12-03 00:00:00 3000 20
7934 MILLER CLERK 7782 1982-01-23 00:00:00 1300 10
14 rows selected.
Elapsed: 00:00:00.01
sys@ORCLPDB01 2023-04-02 20:35:39> exec dbms_workload_repository.create_snapshot();
PL/SQL procedure successfully completed.
Elapsed: 00:00:01.41
sys@ORCLPDB01 2023-04-02 20:35:49> col SQL_TEXT for a45;
sys@ORCLPDB01 2023-04-02 20:36:15> select sql_text,sql_id,version_count,executions from v$sqlarea where sql_text like 'select * from emp%';
SQL_TEXT SQL_ID VERSION_COUNT EXECUTIONS
--------------------------------------------- ------------- ------------- ----------
select * from emp a2dk8bdn0ujx7 1 1
Elapsed: 00:00:00.02
sys@ORCLPDB01 2023-04-02 20:36:40> alter system flush shared_pool;
System altered.
Elapsed: 00:00:00.15
sys@ORCLPDB01 2023-04-02 20:37:17> select sql_text,sql_id,version_count,executions from v$sqlarea where sql_text like 'select * from emp%';
no rows selected
Elapsed: 00:00:00.02
sys@ORCLPDB01 2023-04-02 20:37:51> select * from table(dbms_xplan.display_awr('a2dk8bdn0ujx7'));
no rows selected
Elapsed: 00:00:00.073.sqlplus中的autotrace
4.10046事件
5.10053事件
6.AWR报告或者statspack报告
7.一些现成的脚本