【dbms_xplan.display_cursor包】預設與ADVANCED ALLSTATS LAST PEEKED_BINDS區別

結論1：使用ALL LAST比typical多了Query Block Name / Object Alias和Column Projection Information（列的資訊）

結論2：ADVANCED ALLSTATS LAST PEEKED_BINDS比ALL LAST多了這些內容：outline和NOTE，當然如果使用了繫結變數的話，還有繫結變數資訊

結論3：一般來說ALL LAST就已經夠用了。

使用一個不使用繫結變數的語句來做對比試驗：

select /*weiwei*/ e.ename,d.dname from scott.emp e,scott.dept d where e.deptno=d.deptno;

SQL> SELECT * FROM table (DBMS_XPLAN.DISPLAY_CURSOR);

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

SQL_ID        1qwpbwszr5hwb, child number 0

-------------------------------------

select /*weiwei*/ e.ename,d.dname from scott.emp e,scott.dept d where

e.deptno=d.deptno

Plan hash value: 844388907

----------------------------------------------------------------------------------------

| Id  | Operation                     | Name    | Rows  | Bytes | Cost (%CPU)| Time     |

----------------------------------------------------------------------------------------

|   0 | SELECT STATEMENT             |               |       |       |     6 (100)|               |

|   1 |  MERGE JOIN                     |               |    14 |   308 |     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 |   126 |     4        (25)| 00:00:01 |

|   5 |    TABLE ACCESS FULL             | EMP     |    14 |   126 |     3         (0)| 00:00:01 |

----------------------------------------------------------------------------------------

Predicate Information (identified by operation id):

---------------------------------------------------

   4 - access("E"."DEPTNO"="D"."DEPTNO")

       filter("E"."DEPTNO"="D"."DEPTNO")

24 rows selected.

select sql_id,CHILD_NUMBER,sql_text from v$SQL where sql_text like '%weiwei%' and  sql_text not like '%like%';

獲得SQL_id為1qwpbwszr5hwb,CHILD_NUMBER為0

select * from table(dbms_xplan.display_cursor('1qwpbwszr5hwb',null,'ALL LAST'));

SQL> select * from table(dbms_xplan.display_cursor('1qwpbwszr5hwb',null,'ALL LAST'));

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

SQL_ID        1qwpbwszr5hwb, child number 0

-------------------------------------

select /*weiwei*/ e.ename,d.dname from scott.emp e,scott.dept d where

e.deptno=d.deptno

Plan hash value: 844388907

----------------------------------------------------------------------------------------

| Id  | Operation                     | Name    | Rows  | Bytes | Cost (%CPU)| Time     |

----------------------------------------------------------------------------------------

|   0 | SELECT STATEMENT             |               |       |       |     6 (100)|               |

|   1 |  MERGE JOIN                     |               |    14 |   308 |     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 |   126 |     4        (25)| 00:00:01 |

|   5 |    TABLE ACCESS FULL             | EMP     |    14 |   126 |     3         (0)| 00:00:01 |

----------------------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

   1 - SEL$1

   2 - SEL$1 / D@SEL$1

   3 - SEL$1 / D@SEL$1

   5 - SEL$1 / E@SEL$1

Predicate Information (identified by operation id):

---------------------------------------------------

   4 - access("E"."DEPTNO"="D"."DEPTNO")

       filter("E"."DEPTNO"="D"."DEPTNO")

Column Projection Information (identified by operation id):

-----------------------------------------------------------

   1 - "D"."DNAME"[VARCHAR2,14], "E"."ENAME"[VARCHAR2,10]

   2 - "D"."DEPTNO"[NUMBER,22], "D"."DNAME"[VARCHAR2,14]

   3 - "D".ROWID[ROWID,10], "D"."DEPTNO"[NUMBER,22]

   4 - (#keys=1) "E"."DEPTNO"[NUMBER,22], "E"."ENAME"[VARCHAR2,10]

   5 - "E"."ENAME"[VARCHAR2,10], "E"."DEPTNO"[NUMBER,22]

41 rows selected.

結論1：使用ALL LAST比typical多了Query Block Name / Object Alias和Column Projection Information（列的資訊）

再對比ALL LAST與ADVANCED ALLSTATS LAST PEEKED_BINDS

最後最全的是65行

select * from table(dbms_xplan.display_cursor('1qwpbwszr5hwb',0,'ADVANCED ALLSTATS LAST PEEKED_BINDS'));

SQL> select * from table(dbms_xplan.display_cursor('1qwpbwszr5hwb',0,'ADVANCED ALLSTATS LAST PEEKED_BINDS'));

PLAN_TABLE_OUTPUT

--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

SQL_ID        1qwpbwszr5hwb, child number 0

-------------------------------------

select /*weiwei*/ e.ename,d.dname from scott.emp e,scott.dept d where

e.deptno=d.deptno

Plan hash value: 844388907

--------------------------------------------------------------------------------------------------------------------

| Id  | Operation                     | Name    | E-Rows |E-Bytes| Cost (%CPU)| E-Time        |  OMem |  1Mem | Used-Mem |

--------------------------------------------------------------------------------------------------------------------

|   0 | SELECT STATEMENT             |               |        |        |     6 (100)|                |        |        |           |

|   1 |  MERGE JOIN                     |               |     14 |   308 |     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 |   126 |     4  (25)| 00:00:01 |  2048 |  2048 | 2048        (0)|

|   5 |    TABLE ACCESS FULL             | EMP     |     14 |   126 |     3   (0)| 00:00:01 |        |        |           |

--------------------------------------------------------------------------------------------------------------------

Query Block Name / Object Alias (identified by operation id):

-------------------------------------------------------------

   1 - SEL$1

   2 - SEL$1 / D@SEL$1

   3 - SEL$1 / D@SEL$1

   5 - SEL$1 / E@SEL$1

Outline Data

-------------

  /*+

      BEGIN_OUTLINE_DATA

      IGNORE_OPTIM_EMBEDDED_HINTS

      OPTIMIZER_FEATURES_ENABLE('11.2.0.3')

      DB_VERSION('11.2.0.3')

      OPT_PARAM('query_rewrite_enabled' 'false')

      ALL_ROWS

      OUTLINE_LEAF(@"SEL$1")

      INDEX(@"SEL$1" "D"@"SEL$1" ("DEPT"."DEPTNO"))

      FULL(@"SEL$1" "E"@"SEL$1")

      LEADING(@"SEL$1" "D"@"SEL$1" "E"@"SEL$1")

      USE_MERGE(@"SEL$1" "E"@"SEL$1")

      END_OUTLINE_DATA

  */

Predicate Information (identified by operation id):

---------------------------------------------------

   4 - access("E"."DEPTNO"="D"."DEPTNO")

       filter("E"."DEPTNO"="D"."DEPTNO")

Column Projection Information (identified by operation id):

-----------------------------------------------------------

   1 - "D"."DNAME"[VARCHAR2,14], "E"."ENAME"[VARCHAR2,10]

   2 - "D"."DEPTNO"[NUMBER,22], "D"."DNAME"[VARCHAR2,14]

   3 - "D".ROWID[ROWID,10], "D"."DEPTNO"[NUMBER,22]

   4 - (#keys=1) "E"."DEPTNO"[NUMBER,22], "E"."ENAME"[VARCHAR2,10]

   5 - "E"."ENAME"[VARCHAR2,10], "E"."DEPTNO"[NUMBER,22]

Note

-----

   - Warning: basic plan statistics not available. These are only collected when:

       * hint 'gather_plan_statistics' is used for the statement or

       * parameter 'statistics_level' is set to 'ALL', at session or system level

65 rows selected.

結論2：ADVANCED ALLSTATS LAST PEEKED_BINDS比ALL LAST多了這些內容：outline和NOTE，當然如果使用了繫結變數的話，還有繫結變數資訊