| | 5 | | 5 |00:00:00.01 | 7 |
| 5 | SORT JOIN | | 5 | 5 | 14 |00:00:00.01 | 7 |
| 6 | TABLE ACCESS FULL| SALGRADE | 1 | 5 | 5 |00:00:00.01 | 7 |
-------------------------------------------------------------------------------------------
/*---------------- 修改会话级别的参数statistics_level为typical并验证修改结果----------------*/
SQL> alter session set statistics_level=typical;
SQL> col name format a40
SQL> col value format a25
SQL> col display_value format a25
SQL> select name, value, display_value, isses_modifiable
2 from v$parameter
3 where isses_modifiable = 'TRUE'
4 and name like '%&input_name%';
Enter value for input_name: statistics_level
old 4: and name like '%&input_name%'
new 4: and name like '%statistics_level%'
NAME VALUE DISPLAY_VALUE ISSES
---------------------------------------- ------------------------- ------------------------- -----
statistics_level TYPICAL TYPICAL TRUE
/*-------- 使用提示gather_plan_statistics，并获得其真实执行计划，使用了allstats -rows修饰符控制显示输出---*/
SQL> set pagesize 180
SQL> SELECT /*+ gather_plan_statistics */ ename,dname,loc
2 FROM emp e, dept d |