读undo问题

SQL> drop table test1 purge;



Table dropped.



SQL> create table test1 as select * from dba_objects where 1=2;



Table created.



SQL> insert into test1  select * from dba_objects;



74506 rows created.



SQL> insert into test1  select * from  test1;



74506 rows created.



SQL> /



149012 rows created.



SQL> /



298024 rows created.



SQL> /



596048 rows created.



SQL> /



1192096 rows created.







SQL> select segment_name,bytes/1024/1024 from dba_segments where owner='TEST' and segment_name='TEST1';



SEGMENT_NAME

--------------------------------------------------------------------------------

BYTES/1024/1024

---------------

TEST1

	      9





SQL> set linesize 200

SQL> /



SEGMENT_NAME									  BYTES/1024/1024

--------------------------------------------------------------------------------- ---------------

TEST1												9



SQL> /



SEGMENT_NAME									  BYTES/1024/1024

--------------------------------------------------------------------------------- ---------------

TEST1											       34



SQL> /



SEGMENT_NAME									  BYTES/1024/1024

--------------------------------------------------------------------------------- ---------------

TEST1											       88



SQL> /



SEGMENT_NAME									  BYTES/1024/1024

--------------------------------------------------------------------------------- ---------------

TEST1											      128



SQL> /



SEGMENT_NAME									  BYTES/1024/1024

--------------------------------------------------------------------------------- ---------------

TEST1											      152



SQL> /



SEGMENT_NAME									  BYTES/1024/1024

--------------------------------------------------------------------------------- ---------------

TEST1											      270





随着数据的插入,虽然没有提交,但是表的大小不断增大





SQL> /



       SID EVENT

---------- ----------------------------------------------------------------

	38 db file sequential read

看到了大量的db file sequential read,可以判定是读的undo块