Question

我在使用dba_hist_seg_stat时遇到问题。它不会在新创建的表上记录有关该操作的信息。以下是完整的示例。我创建了一个表和3行，创建了一个快照，对一个表进行了很少的操作，创建了第二个快照，最后我试图为一个新表查找一个统计信息，但是选择什么也找不到。这是什么问题？我注意到经过一些操作后，我可以看到一些统计信息，但它是随机发生的。

 -- create test data
drop table testXX
/
  create table testXX 
(
   a       VARCHAR2(8),
   b   VARCHAR2(255),
   c         INTEGER
)
   tablespace SDATA
/

 INSERT INTO testXX (a,b,c) VALUES ('23423424','234234', 2222) 
 /
 INSERT INTO testXX (a,b,c) VALUES ('13423424','234234', 2222) 
/
 INSERT INTO testXX (a,b,c) VALUES ('03423424','234234', 2222) 
/
 INSERT INTO testXX (a,b,c) VALUES ('23423424','234234', 2222) 
 /
 INSERT INTO testXX (a,b,c) VALUES ('13423424','234234', 2222) 
/
 INSERT INTO testXX (a,b,c) VALUES ('03423424','234234', 2222) 
/
 INSERT INTO testXX (a,b,c) VALUES ('23423424','234234', 2222) 
 /
 INSERT INTO testXX (a,b,c) VALUES ('13423424','234234', 2222) 
/
 INSERT INTO testXX (a,b,c) VALUES ('03423424','234234', 2222) 
/
 INSERT INTO testXX (a,b,c) VALUES ('03423424','234234', 2222) 
/

-- creating snapshoot
EXEC dbms_workload_repository.create_snapshot;
/
-- few sample select

SELECT * FROM testXX
/

SELECT * FROM testXX WHERE a='23423424'
/

-- creating final snapshoot
EXEC dbms_workload_repository.create_snapshot;


select
    owner,
    object_name,                                  
 LOGICAL_READS_DELTA,                                   
 BUFFER_BUSY_WAITS_DELTA    ,                     
 DB_BLOCK_CHANGES_DELTA   ,                       
 PHYSICAL_READS_DELTA     ,                            
 PHYSICAL_WRITES_DELTA      ,                         
 PHYSICAL_READS_DIRECT_DELTA    ,             
 PHYSICAL_WRITES_DIRECT_DELTA      
from
   dba_hist_seg_stat       s,
   dba_hist_seg_stat_obj   o,
   dba_hist_snapshot       sn
where
   o.object_name = 'TESTXX'
and
   s.obj# = o.obj#
AND 
   S.SNAP_ID=SN.SNAP_ID
AND
    SN.SNAP_ID=(SELECT MAX(SNAP_ID) FROM DBA_HIST_SNAPSHOT)
order by
   3  desc
/


    and
       s.obj# = o.obj#
    order by
       3  desc;

Oracle dba_hist_seg_stat不存储有关所有表上操作的信息，为什么？

0 个答案: