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看下面小练习,告诉你如何用oracle命令查看执行计划.

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1.想要查看执法计划的SQL语句:

explain plan for select t.*, t.rowid from A5 t where t.l = '101214' and t.k like '%8号' order by i ;

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2.查看此SQL语句的执行计划:

select * from table(dbms_xplan.display);

执行结果如下:

PLAN_TABLE_OUTPUT
--------------------------------------------
Plan hash value: 1156097717
---------------------------------------
| Id? | Operation????????? | Name | Rows? | Bytes | Cost (%CPU)| Time???? |
---------------------------------------
|?? 0 | SELECT STATEMENT?? |?????   |??? 12 |? 1524 |??? 71?? (3)| 00:00:01 |
|?? 1 |? SORT ORDER BY????  |?????   |??? 12 |? 1524 |??? 71?? (3)| 00:00:01 |
|*? 2 |?? TABLE ACCESS FULL| A5?? |??? 12 |? 1524 |??? 70?? (2)| 00:00:01 |
----------------------------------------
Note
-----
   - 'PLAN_TABLE' is old version
 
12 rows selected

'PLAN_TABLE' is old version : 这句话告诉我们,PLAN_TABLE的版本太旧,需要重新生成.

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3.重新生成PLAN_TABLE表:

-- 删除表
drop table PLAN_TABLE;
-- 新建表
@D:\oracle\product\10.2.0\db_1\RDBMS\ADMIN\utlxplan.sql;

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4.查看执行计划:

select * from table(dbms_xplan.display);

结果如下:

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PLAN_TABLE_OUTPUT
--------------------------------------------
Plan hash value: 1156097717
---------------------------------------
| Id  | Operation          | Name | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------
|   0 | SELECT STATEMENT   |      |    12 |  1524 |    71   (3)| 00:00:01 |
|   1 |  SORT ORDER BY     |      |    12 |  1524 |    71   (3)| 00:00:01 |
|*  2 |   TABLE ACCESS FULL| A5   |    12 |  1524 |    70   (2)| 00:00:01 |
---------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
   2 - filter("T"."L"='101214' AND "T"."K" LIKE '%8号')
 
14 rows selected

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1 楼 至尊宝_唯一 22 小时前  

个人还是更喜欢在PL/SQL developer中查看，查看的信息还可以个性化定制，挺不错的