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标题:autotrace显示Statistics很多信息为0
作者:惜分飞©版权所有[未经本人同意,不得以任何形式转载,否则有进一步追究法律责任的权利.]
一朋友使用autotrace查看数据库执行计划发现结果如下,Statistics中很多信息为0,这个肯定是不正常现象,什么都可以为0,consistent gets也不可能为0.
SQL> set autot on SQL> select count(*) from RACV_DATA.PARTY_DUMMY; COUNT(*) ---------- 47 Elapsed: 00:00:00.00 Execution Plan ---------------------------------------------------------- Plan hash value: 3621440939 -------------------------------------------------------------------------- | Id | Operation | Name | Rows | Cost (%CPU)| Time | -------------------------------------------------------------------------- | 0 | SELECT STATEMENT | | 1 | 3 (0)| 00:00:01 | | 1 | SORT AGGREGATE | | 1 | | | | 2 | TABLE ACCESS FULL| PARTY_DUMMY | 47 | 3 (0)| 00:00:01 | -------------------------------------------------------------------------- Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 0 consistent gets 0 physical reads 0 redo size 0 bytes sent via SQL*Net to client 0 bytes received via SQL*Net from client 0 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 1 rows processed
解决方法
SQL> select owner,object_name from dba_objects where object_name='PLAN_TABLE'; no rows selected SQL> @?/rdbms/admin/utlxplan.sql Table created.
重新查看Statistics信息
Statistics ---------------------------------------------------------- 0 recursive calls 0 db block gets 7 consistent gets 0 physical reads 0 redo size 522 bytes sent via SQL*Net to client 524 bytes received via SQL*Net from client 2 SQL*Net roundtrips to/from client 0 sorts (memory) 0 sorts (disk) 1 rows processed