[20230308]versions伪列versions_starttime疑问2.txt

--//上个星期对生产系统redo做了一个转储，主要是想分析为什么这套系统每天产生的日志有点大。
--//当我使用versions方式查询遇到一个情况，

1.问题引出
$ cat aa1.txt
set numw 12
column id new_value v_id
column item_id new_value v_item_id
column scn1 new_value  v_scn1
column scn2 new_value  v_scn2

set term off
select current_scn-1e4 scn1 from v$database;
select id,max(item_id) item_id from LIS_RESULT where id = (select max(id) from LIS_RESULT ) group by id;

host sleep &&1
select current_scn scn2 from v$database;
set term on

SELECT versions_starttime
             ,versions_endtime
             ,versions_xid
             ,versions_operation
             ,versions_startscn
             ,versions_endscn
             ,lis_result.id
             ,lis_result.item_id
FROM LIS_RESULT VERSIONS BETWEEN scn &v_scn1 and &v_scn2
--  FROM LIS_RESULT VERSIONS BETWEEN TIMESTAMP sysdate-1/1440 and sysdate
   WHERE  id = &&v_id and  item_id = &&v_item_id
--  order by VERSIONS_STARTSCN
;
--//注:选择sleep N一定时间,正常情况选择3秒比较稳妥.
--//另外说明字段id,item_id组成主键.

SYS@192.168.100.235:1521/orcl> @ aa1.txt 3
VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID      ITEM_ID
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ ------------
2023-03-01 09:08:49.                      02000100EDE51300 U       44616150499                     26961554         7436
2023-03-01 09:08:46. 2023-03-01 09:08:49. 05000B0042F01500 I       44616150170     44616150499     26961554         7436
--//相差3秒.

SYS@192.168.100.235:1521/orcl> @ aa1.txt 3
VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID      ITEM_ID
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ ------------
2023-03-01 09:09:52.                      0C001900379C1E00 U       44616170991                     26961673         3431
2023-03-01 09:09:52. 2023-03-01 09:09:52. 0100110024371600 I       44616170950     44616170991     26961673         3431
--//看versions_operation列,先insert然后update,看VERSIONS_STARTTIME列几乎在同一个时间点完成或者相差3秒马上修改.
--//我执行许多次要么相差3秒,要么基本相差0秒，3秒的出现到底是如何引起的，我开始怀疑IMU，难道时间是通过scn转换而来，存在很大的误差吗？
--//在测试环境写一个例子看看：

1.环境:
SCOTT@book> @ver1
PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

2.测试例子:
SCOTT@book> create table t SEGMENT CREATION IMMEDIATE as select rownum id ,lpad('a',500,'a') vc from dual where 1=0;
Table created.
--//分析略.

SCOTT@book>  @ o2 t
owner object_name object_type SEG_PART_NAME status       OID      D_OID CREATED             LAST_DDL_TIME
----- ----------- ----------- ------------- --------- ------ ---------- ------------------- -------------------
SCOTT T           TABLE                     VALID     339517     339517 2023-03-03 10:01:23 2023-03-06 09:30:06

$ cat dumpreodo2.sql
column member new_value v_member
column member noprint
set numw 12
--//pause alter system switch logfile ;
--//pause alter system archive log current;
--//12c不允许在pluggable database执行以上命令,可以在别的回话执行然后继续。
--//SELECT  member FROM v$log a, v$logfile b WHERE a.group#(+) = b.group# and a.STATUS='CURRENT' and rownum=1;

column scn1 new_value v_scn1
column scn2 new_value v_scn2
column scn3 new_value v_scn3
select current_scn scn1  from v$database;

--//以下DML操作内容:
insert into t  select rownum id ,lpad('a',50,'a') vc from dual connect by level<=5;
commit;
host sleep 3
select current_scn scn3  from v$database;

update t set vc=rpad(id||'b',50,'b') where id=1;
host sleep 1
commit ;
update t set vc=rpad(id||'b',50,'b') where id=2;
host sleep 1
commit ;
update t set vc=rpad(id||'b',50,'b') where id=3;
host sleep 1
commit ;
update t set vc=rpad(id||'b',50,'b') where id=4;
host sleep 1
commit ;
update t set vc=rpad(id||'b',50,'b') where id=5;
host sleep 1
commit ;
host sleep 1

select current_scn  scn2 from v$database;

--//prompt alter system dump logfile '&&v_member' scn min &&v_curr1 scn max &&v_curr2;
--//alter system dump logfile '&&v_member' scn min &&v_curr1 scn max &&v_curr2;
prompt alter system dump redo scn min &&v_scn1 scn max &&v_scn2 ;;
alter system dump redo scn min &&v_scn1 scn max &&v_scn2 ;

$ cat vv2.txt
column vc format a100
SELECT versions_starttime
             ,versions_endtime
             ,versions_xid
             ,versions_operation
             ,versions_startscn
             ,versions_endscn
             ,t.*
FROM t VERSIONS BETWEEN scn &v_scn1 and &v_scn2
--FROM t  VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE
order by versions_startscn  nulls first,id
;

SELECT versions_starttime
             ,versions_endtime
             ,versions_xid
             ,versions_operation
             ,versions_startscn
             ,versions_endscn
             ,t.*
FROM t VERSIONS BETWEEN scn &v_scn1 and &v_scn3
--FROM t  VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE
order by versions_startscn  nulls first,id
;

SELECT versions_starttime
             ,versions_endtime
             ,versions_xid
             ,versions_operation
             ,versions_startscn
             ,versions_endscn
             ,t.*
FROM t VERSIONS BETWEEN scn &v_scn3 and &v_scn2
--FROM t  VERSIONS BETWEEN SCN MINVALUE AND MAXVALUE
order by versions_startscn nulls first,id
;

3.执行结果:
SCOTT@book> @ dumpredo2.sql
        SCN1
------------
 13489327157
5 rows created.
Commit complete.
        SCN3
------------
 13489327162
1 row updated.
Commit complete.
1 row updated.
Commit complete.
1 row updated.
Commit complete.
1 row updated.
Commit complete.
1 row updated.
Commit complete.
        SCN2
------------
 13489327174

alter system dump redo scn min  13489327157 scn max  13489327174 ;
System altered.

SCOTT@book> @ vv2.txt
VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID VC
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ --------------------------------------------------
2023-03-08 09:02:41. 2023-03-08 09:02:44. 0A000C000A5B0500 I       13489327158     13489327164            1 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41. 2023-03-08 09:02:47. 0A000C000A5B0500 I       13489327158     13489327166            2 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41. 2023-03-08 09:02:47. 0A000C000A5B0500 I       13489327158     13489327168            3 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41. 2023-03-08 09:02:47. 0A000C000A5B0500 I       13489327158     13489327170            4 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41. 2023-03-08 09:02:50. 0A000C000A5B0500 I       13489327158     13489327172            5 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:44.                      0A001E0097580500 U       13489327164                            1 1bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:47.                      0A001200E85A0500 U       13489327166                            2 2bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:47.                      0A000000FA5A0500 U       13489327168                            3 3bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:47.                      0A001B00F95A0500 U       13489327170                            4 4bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:50.                      0A0006000F5B0500 U       13489327172                            5 5bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
10 rows selected.
--//VERSIONS_STARTTIME不准!!注意有3条记录的VERSIONS_STARTTIME都是2023-03-08 09:02:47.

VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID VC
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ --------------------------------------------------
2023-03-08 09:02:41.                      0A000C000A5B0500 I       13489327158                            1 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41.                      0A000C000A5B0500 I       13489327158                            2 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41.                      0A000C000A5B0500 I       13489327158                            3 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41.                      0A000C000A5B0500 I       13489327158                            4 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:41.                      0A000C000A5B0500 I       13489327158                            5 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID VC
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ --------------------------------------------------
                     2023-03-08 09:02:44.                                          13489327164            1 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:02:47.                                          13489327166            2 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:02:47.                                          13489327168            3 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:02:47.                                          13489327170            4 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:02:50.                                          13489327172            5 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:02:44.                      0A001E0097580500 U       13489327164                            1 1bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:47.                      0A001200E85A0500 U       13489327166                            2 2bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:47.                      0A000000FA5A0500 U       13489327168                            3 3bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:47.                      0A001B00F95A0500 U       13489327170                            4 4bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:02:50.                      0A0006000F5B0500 U       13489327172                            5 5bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
10 rows selected.

--//换一句话将VERSIONS_STARTTIME的时间不是绝对准确，应该更多依靠scn判断。

$ egrep "^REDO RECORD|^CHANGE" /u01/app/oracle/diag/rdbms/book/book/trace/book_ora_13181.trc
REDO RECORD - Thread:1 RBA: 0x001499.00011575.0010 LEN: 0x0074 VLD: 0x05
CHANGE #1 TYP:2 CLS:1 AFN:4 DBA:0x01009ce3 OBJ:339600 SCN:0x0003.2406cc25 SEQ:1 OP:4.1 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x001499.00011575.0084 LEN: 0x0424 VLD: 0x09
CHANGE #1 TYP:0 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.23fe5652 SEQ:2 OP:11.11 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc25 SEQ:1 OP:5.2 ENC:0 RBL:0
CHANGE #3 TYP:0 CLS:1 AFN:4 DBA:0x01009ce3 OBJ:339600 SCN:0x0003.2406cc35 SEQ:1 OP:10.2 ENC:0 RBL:0
CHANGE #4 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc36 SEQ:1 OP:5.4 ENC:0 RBL:0
CHANGE #5 TYP:0 CLS:36 AFN:3 DBA:0x00c030d1 OBJ:4294967295 SCN:0x0003.2406cc23 SEQ:10 OP:5.1 ENC:0 RBL:0
CHANGE #6 TYP:0 CLS:36 AFN:3 DBA:0x00c030d1 OBJ:4294967295 SCN:0x0003.2406cc36 SEQ:1 OP:5.1 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x001499.0001157b.0010 LEN: 0x02a4 VLD: 0x0d
CHANGE #1 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cc36 SEQ:2 OP:11.19 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc36 SEQ:2 OP:5.2 ENC:0 RBL:0
CHANGE #3 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc3c SEQ:1 OP:5.4 ENC:0 RBL:0
CHANGE #4 TYP:0 CLS:36 AFN:3 DBA:0x00c030d0 OBJ:4294967295 SCN:0x0003.2406cb90 SEQ:4 OP:5.1 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x001499.0001157d.0010 LEN: 0x0294 VLD: 0x0d
CHANGE #1 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cc3c SEQ:2 OP:11.19 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc3c SEQ:2 OP:5.2 ENC:0 RBL:0
CHANGE #3 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc3e SEQ:1 OP:5.4 ENC:0 RBL:0
CHANGE #4 TYP:0 CLS:36 AFN:3 DBA:0x00c030d0 OBJ:4294967295 SCN:0x0003.2406cc3c SEQ:1 OP:5.1 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x001499.0001157f.0010 LEN: 0x02c4 VLD: 0x0d
CHANGE #1 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cc3e SEQ:2 OP:11.19 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc3e SEQ:2 OP:5.2 ENC:0 RBL:0
CHANGE #3 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc40 SEQ:1 OP:5.4 ENC:0 RBL:0
CHANGE #4 TYP:0 CLS:36 AFN:3 DBA:0x00c030d0 OBJ:4294967295 SCN:0x0003.2406cc3e SEQ:1 OP:5.1 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x001499.00011581.0010 LEN: 0x0294 VLD: 0x0d
CHANGE #1 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cc40 SEQ:2 OP:11.19 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc40 SEQ:2 OP:5.2 ENC:0 RBL:0
CHANGE #3 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc42 SEQ:1 OP:5.4 ENC:0 RBL:0
CHANGE #4 TYP:0 CLS:36 AFN:3 DBA:0x00c030d0 OBJ:4294967295 SCN:0x0003.2406cc40 SEQ:1 OP:5.1 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x001499.00011583.0010 LEN: 0x02c4 VLD: 0x0d
CHANGE #1 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cc42 SEQ:2 OP:11.19 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc42 SEQ:2 OP:5.2 ENC:0 RBL:0
CHANGE #3 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cc44 SEQ:1 OP:5.4 ENC:0 RBL:0
CHANGE #4 TYP:0 CLS:36 AFN:3 DBA:0x00c030d0 OBJ:4294967295 SCN:0x0003.2406cc42 SEQ:1 OP:5.1 ENC:0 RBL:0

3.我开始以为是IMU的影响,关闭IMU测试看看.
SYS@book> alter database flashback on;
Database altered.

SCOTT@book> delete from t ;
5 rows deleted.

SCOTT@book> commit ;
Commit complete.

--//重复测试.
SCOTT@book> @ dumpredo2.sql
        SCN1
------------
 13489328029
5 rows created.
Commit complete.
        SCN3
------------
 13489328034
1 row updated.
Commit complete.
1 row updated.
Commit complete.
1 row updated.
Commit complete.
1 row updated.
Commit complete.
1 row updated.
Commit complete.
        SCN2
------------
 13489328046

alter system dump redo scn min  13489328029 scn max  13489328046 ;
System altered.

SCOTT@book> @ vv2.txt
VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID VC
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ --------------------------------------------------
2023-03-08 09:09:28. 2023-03-08 09:09:32. 0100090056830000 I       13489328030     13489328036            1 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28. 2023-03-08 09:09:32. 0100090056830000 I       13489328030     13489328038            2 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28. 2023-03-08 09:09:35. 0100090056830000 I       13489328030     13489328040            3 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28. 2023-03-08 09:09:35. 0100090056830000 I       13489328030     13489328042            4 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28. 2023-03-08 09:09:35. 0100090056830000 I       13489328030     13489328044            5 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:32.                      0A000A0073350500 U       13489328036                            1 1bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:32.                      0A001700255B0500 U       13489328038                            2 2bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:35.                      0A001100685A0500 U       13489328040                            3 3bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:35.                      010019004F830000 U       13489328042                            4 4bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:35.                      06000B00AD870000 U       13489328044                            5 5bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb

10 rows selected.

VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID VC
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ --------------------------------------------------
2023-03-08 09:09:28.                      0100090056830000 I       13489328030                            1 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28.                      0100090056830000 I       13489328030                            2 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28.                      0100090056830000 I       13489328030                            3 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28.                      0100090056830000 I       13489328030                            4 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:28.                      0100090056830000 I       13489328030                            5 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa

VERSIONS_STARTTIME   VERSIONS_ENDTIME     VERSIONS_XID     V VERSIONS_STARTSCN VERSIONS_ENDSCN           ID VC
-------------------- -------------------- ---------------- - ----------------- --------------- ------------ --------------------------------------------------
                     2023-03-08 09:09:32.                                          13489328036            1 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:09:32.                                          13489328038            2 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:09:35.                                          13489328040            3 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:09:35.                                          13489328042            4 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
                     2023-03-08 09:09:35.                                          13489328044            5 aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2023-03-08 09:09:32.                      0A000A0073350500 U       13489328036                            1 1bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:32.                      0A001700255B0500 U       13489328038                            2 2bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:35.                      0A001100685A0500 U       13489328040                            3 3bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:35.                      010019004F830000 U       13489328042                            4 4bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
2023-03-08 09:09:35.                      06000B00AD870000 U       13489328044                            5 5bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb
10 rows selected.
--//还是一样.

SCOTT@book> @ ttt
tracefile_identifier = /u01/app/oracle/diag/rdbms/book/book/trace/book_ora_13256.trc

$ egrep "^REDO RECORD|^CHANGE" /u01/app/oracle/diag/rdbms/book/book/trace/book_ora_13256.trc
REDO RECORD - Thread:1 RBA: 0x00149a.00000014.0010 LEN: 0x02cc VLD: 0x05
CHANGE #1 TYP:0 CLS:17 AFN:3 DBA:0x00c00080 OBJ:4294967295 SCN:0x0003.2406cf6e SEQ:1 OP:5.2 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:18 AFN:3 DBA:0x00c000a9 OBJ:4294967295 SCN:0x0003.2406cf6d SEQ:1 OP:5.1 ENC:0 RBL:0
CHANGE #3 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cf7d SEQ:1 OP:11.11 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000015.00ec LEN: 0x0048 VLD: 0x01
CHANGE #1 TYP:2 CLS:1 AFN:4 DBA:0x01009ce3 OBJ:339600 SCN:0x0003.2406cf7d SEQ:1 OP:4.1 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000015.0134 LEN: 0x017c VLD: 0x01
CHANGE #1 TYP:0 CLS:18 AFN:3 DBA:0x00c000a9 OBJ:4294967295 SCN:0x0003.2406cf9d SEQ:1 OP:5.1 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:1 AFN:4 DBA:0x01009ce3 OBJ:339600 SCN:0x0003.2406cf9d SEQ:1 OP:10.2 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000016.00c0 LEN: 0x0060 VLD: 0x01
CHANGE #1 TYP:0 CLS:17 AFN:3 DBA:0x00c00080 OBJ:4294967295 SCN:0x0003.2406cf9d SEQ:1 OP:5.4 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000019.0010 LEN: 0x027c VLD: 0x05
CHANGE #1 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cf90 SEQ:1 OP:5.2 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:36 AFN:3 DBA:0x00c030d6 OBJ:4294967295 SCN:0x0003.2406cf8f SEQ:1 OP:5.1 ENC:0 RBL:0
CHANGE #3 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cf9e SEQ:1 OP:11.19 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.0000001b.0010 LEN: 0x008c VLD: 0x05
CHANGE #1 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cfa2 SEQ:1 OP:5.4 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.0000001c.0010 LEN: 0x024c VLD: 0x05
CHANGE #1 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cfa4 SEQ:1 OP:5.2 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:36 AFN:3 DBA:0x00c030d6 OBJ:4294967295 SCN:0x0003.2406cfa2 SEQ:1 OP:5.1 ENC:0 RBL:0
CHANGE #3 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cfa4 SEQ:1 OP:11.19 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.0000001d.006c LEN: 0x0060 VLD: 0x01
CHANGE #1 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cfa5 SEQ:1 OP:5.4 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.0000001e.0010 LEN: 0x027c VLD: 0x05
CHANGE #1 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cfa6 SEQ:1 OP:5.2 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:36 AFN:3 DBA:0x00c030d6 OBJ:4294967295 SCN:0x0003.2406cfa5 SEQ:1 OP:5.1 ENC:0 RBL:0
CHANGE #3 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cfa6 SEQ:1 OP:11.19 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.0000001f.009c LEN: 0x0060 VLD: 0x01
CHANGE #1 TYP:0 CLS:35 AFN:3 DBA:0x00c00110 OBJ:4294967295 SCN:0x0003.2406cfa7 SEQ:1 OP:5.4 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000020.0010 LEN: 0x024c VLD: 0x05
CHANGE #1 TYP:0 CLS:17 AFN:3 DBA:0x00c00080 OBJ:4294967295 SCN:0x0003.2406cf9e SEQ:1 OP:5.2 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:18 AFN:3 DBA:0x00c000a9 OBJ:4294967295 SCN:0x0003.2406cf9d SEQ:2 OP:5.1 ENC:0 RBL:0
CHANGE #3 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cfa8 SEQ:1 OP:11.19 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000021.006c LEN: 0x0060 VLD: 0x01
CHANGE #1 TYP:0 CLS:17 AFN:3 DBA:0x00c00080 OBJ:4294967295 SCN:0x0003.2406cfa9 SEQ:1 OP:5.4 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000022.0010 LEN: 0x027c VLD: 0x05
CHANGE #1 TYP:0 CLS:27 AFN:3 DBA:0x00c000d0 OBJ:4294967295 SCN:0x0003.2406cf4c SEQ:1 OP:5.2 ENC:0 RBL:0
CHANGE #2 TYP:0 CLS:28 AFN:3 DBA:0x00c003fd OBJ:4294967295 SCN:0x0003.2406cf49 SEQ:11 OP:5.1 ENC:0 RBL:0
CHANGE #3 TYP:2 CLS:1 AFN:4 DBA:0x010008a5 OBJ:339517 SCN:0x0003.2406cfaa SEQ:1 OP:11.19 ENC:0 RBL:0
REDO RECORD - Thread:1 RBA: 0x00149a.00000023.009c LEN: 0x0060 VLD: 0x01
CHANGE #1 TYP:0 CLS:27 AFN:3 DBA:0x00c000d0 OBJ:4294967295 SCN:0x0003.2406cfab SEQ:1 OP:5.4 ENC:0 RBL:0

--//注意看关闭IMU的日志输出顺序出现不同.