如何獲得詳細的解釋計劃？

Question

我在過去的工作的管理工作室，並記住解釋/查詢計劃是描述像以前那樣告訴

1）順序語句將被解僱

2）行數由每個語句

返回

我使用OracleSQL開發人員的「解釋計劃」，但我沒有看到上述功能。有沒有其他好的免費工具？

Answer 1

Order in which statements will be fired

Adrian Billington已經建立了一個「XPlan Utility」，延長DBMS_XPLAN的輸出以包括以下步驟的執行順序。以下輸出顯示了默認輸出與Adrian的XPlan實用程序產生的輸出之間的差異。

例如，

EXPLAIN PLAN FOR 
SELECT * 
FROM emp e, dept d 
WHERE e.deptno = d.deptno 
AND e.ename = 'SMITH'; 

SET LINESIZE 130 

-- Default Output 
SELECT * FROM TABLE(DBMS_XPLAN.DISPLAY); 

PLAN_TABLE_OUTPUT 
---------------------------------------------------------------------------------------- 
Plan hash value: 3625962092 

---------------------------------------------------------------------------------------- 
| Id | Operation     | Name | Rows | Bytes | Cost (%CPU)| Time  | 
---------------------------------------------------------------------------------------- 
| 0 | SELECT STATEMENT    |   |  1 | 58 |  3 (0)| 00:00:53 | 
| 1 | NESTED LOOPS    |   |  |  |   |   | 
| 2 | NESTED LOOPS    |   |  1 | 58 |  3 (0)| 00:00:53 | 
|* 3 | TABLE ACCESS FULL   | EMP  |  1 | 38 |  2 (0)| 00:00:35 | 
|* 4 | INDEX UNIQUE SCAN   | PK_DEPT |  1 |  |  0 (0)| 00:00:01 | 
| 5 | TABLE ACCESS BY INDEX ROWID| DEPT |  1 | 20 |  1 (0)| 00:00:18 | 
---------------------------------------------------------------------------------------- 

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

    3 - filter("E"."ENAME"='SMITH') 
    4 - access("E"."DEPTNO"="D"."DEPTNO") 

18 rows selected. 

SQL> 

讓我們來看看擴展計劃中看到的步驟的順序。見ORD柱：

-- XPlan Utility output 
@xplan.display.sql 

PLAN_TABLE_OUTPUT 
---------------------------------------------------------------------------------------------------- 
Plan hash value: 3625962092 

---------------------------------------------------------------------------------------------------- 
| Id | Pid | Ord | Operation     | Name  | Rows | Bytes | Cost (%CPU)| Time  | 
---------------------------------------------------------------------------------------------------- 
| 0 |  | 6 | SELECT STATEMENT    |    |  1 | 58 |  3 (0)| 00:00:53 | 
| 1 | 0 | 5 | NESTED LOOPS    |    |  |  |   |   | 
| 2 | 1 | 3 | NESTED LOOPS    |    |  1 | 58 |  3 (0)| 00:00:53 | 
|* 3 | 2 | 1 | TABLE ACCESS FULL   | EMP   |  1 | 38 |  2 (0)| 00:00:35 | 
|* 4 | 2 | 2 | INDEX UNIQUE SCAN   | PK_DEPT  |  1 |  |  0 (0)| 00:00:01 | 
| 5 | 1 | 4 | TABLE ACCESS BY INDEX ROWID| DEPT  |  1 | 20 |  1 (0)| 00:00:18 | 
---------------------------------------------------------------------------------------------------- 

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

    3 - filter("E"."ENAME"='SMITH') 
    4 - access("E"."DEPTNO"="D"."DEPTNO") 

About 
------ 
    - XPlan v1.2 by Adrian Billington (http://www.oracle-developer.net) 


18 rows selected. 

SQL> 

Number of rows return by each statement

在SQL開發，則解釋計劃窗口有基數列這說明行數的。使用DBMS_XPLAN，可以以可讀格式顯示。 行的列顯示的行數。

請參閱How to create and display explain plan in SQL*Plus。幾個很好的例子和用法here。