--测试数据库版本

SQL>select* fromv$version;

BANNER

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

OracleDatabase11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production

PL/SQL Release 11.2.0.3.0 - Production

CORE    11.2.0.3.0      Production

TNSforSolaris: Version 11.2.0.3.0 - Production

NLSRTL Version 11.2.0.3.0 - Production

--_smu_debug_mode值

SQL>selecta.ksppinm name,b.ksppstvl value

2   fromx$ksppi a,x$ksppcv b

3  wherea.inst_id = USERENV ('Instance')

4    andb.inst_id = USERENV ('Instance')

5    anda.indx = b.indx

6    andupper(a.ksppinm)LIKEupper('%¶m%')

7 orderby name;

Enter value forparam: _smu_debug_mode

old   6:    andupper(a.ksppinm)LIKEupper('%¶m%')

new   6:    andupper(a.ksppinm)LIKEupper('%_smu_debug_mode%')

NAME                            VALUE

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

_smu_debug_mode                  0

--undo管理模式

SQL> show parameter undo;

NAME                                TYPE        VALUE

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

undo_management                      string      AUTO

undo_retention                      integer    900

undo_tablespace                      string      UNDOTBS1

--指定回滚段(查询dba_rollback_segs得到回滚段名称)

SQL> settransaction use rollbacksegment "_SYSSMU7_1887299474$";

Transactionset.

SQL>deletefrom t whererownum<10;

9rowsdeleted.

--查询使用回滚段

SQL>selectXIDUSN fromV$TRANSACTION;

XIDUSN

----------

9

SQL>select* fromv$version;

BANNER

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

OracleDatabase11g Enterprise Edition Release 11.2.0.3.0 - Production

PL/SQL Release 11.2.0.3.0 - Production

CORE    11.2.0.3.0      Production

TNSfor32-bitWindows: Version 11.2.0.3.0 - Production

NLSRTL Version 11.2.0.3.0 - Production

SQL> show parameter undo;

NAME                                TYPE                VALUE

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

undo_management                      string       AUTO

undo_retention                      integer     900

undo_tablespace                      string       undo_new

SQL>selecta.ksppinm name,b.ksppstvl value

2   fromx$ksppi a,x$ksppcv b

3  wherea.inst_id = USERENV ('Instance')

4    andb.inst_id = USERENV ('Instance')

5    anda.indx = b.indx

6    andupper(a.ksppinm)LIKEupper('%¶m%')

7 orderby name;

Enter value forparam: _smu_debug_mode

old   6:    andupper(a.ksppinm)LIKEupper('%¶m%')

new   6:    andupper(a.ksppinm)LIKEupper('%_smu_debug_mode%')

NAME                            VALUE

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

_smu_debug_mode                  45

/*

使用altersystem set"_smu_debug_mode" = 45;配置

注意:该参数只能在system级别配置

*/

--测试表

SQL>createtable t_xifenfei

2 as

3 select* fromdba_objects;

Tablecreated.

--指定回滚段

SQL>settransaction use rollbacksegment "_SYSSMU15_1680736333$";

Transactionset.

SQL>deletefrom t_xifenfei whererownum<10;

9rowsdeleted.

--查询事务回滚段

SQL>selectXIDUSN fromV$TRANSACTION;

XIDUSN

----------

15

SQL>commit;

Commitcomplete.

--再次指定回滚段

SQL>settransaction use rollbacksegment "_SYSSMU17_527554872$";

Transactionset.

SQL>deletefrom t_xifenfei whererownum<10;

9rowsdeleted.

--查询事务回滚段

SQL>selectXIDUSN fromV$TRANSACTION;

XIDUSN

----------

17