如何开启Oracle block change tracking功能?

sys@TESTDB> alter system set db_create_file_dest='/u01/app/oracle/self_set/omf_dest' scope=both;

System altered.

sys@TESTDB> show parameter db_create

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
db_create_file_dest                  string      /u01/app/oracle/self_set/omf_d
                                                 est
db_create_online_log_dest_1          string
db_create_online_log_dest_2          string
db_create_online_log_dest_3          string
db_create_online_log_dest_4          string
db_create_online_log_dest_5          string
sys@TESTDB> alter database enable  block change tracking;

Database altered.

sys@TESTDB> 

 SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING；

由于没有指定存放路径，那么会按照Oracle Managed Files (OMF)参数DB_CREATE_FILE_DEST 指定的路径Oracle managed file (OMF)

A file that is created automatically by the Oracle database server when it is needed and automatically deleted when it is no longer needed.

如何判断你的数据库是否为支持OMF

SQL> show parameter db_create_file_dest;

如果Value 为空则不支持，有值则支持。