读undo问题

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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      9SQL> set linesize 200SQL> /SEGMENT_NAME  BYTES/1024/1024--------------------------------------------------------------------------------- ---------------TEST19SQL> /SEGMENT_NAME  BYTES/1024/1024--------------------------------------------------------------------------------- ---------------TEST1       34SQL> /SEGMENT_NAME  BYTES/1024/1024--------------------------------------------------------------------------------- ---------------TEST1       88SQL> /SEGMENT_NAME  BYTES/1024/1024--------------------------------------------------------------------------------- ---------------TEST1      128SQL> /SEGMENT_NAME  BYTES/1024/1024--------------------------------------------------------------------------------- ---------------TEST1      152SQL> /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
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