db1:
SQL> select owner,table_name,tablespace_name from dba_tables
2 where table_name = 'AUD$';

OWNER TABLE_NAME TABLESPACE_NAME
------------------------------ ------------------------------ ------------------------------
SYS AUD$ SYSAUX

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
CORE 11.2.0.4.0 Production
TNS for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production


db2:
SQL> select owner,table_name,tablespace_name from dba_tables
2 where table_name = 'AUD$';

OWNER TABLE_NAME TABLESPACE_NAME
------------------------------ ------------------------------ ------------------------------
SYSTEM AUD$ SYSAUX

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
CORE 11.2.0.4.0 Production
TNS for Linux: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production

为什么2个数据库的审计表aud$，一个在sys下面，一个在system下，而且两个数据库是相同的版本