dg切换操作文档

SQL> SELECT TO_CHAR(STANDBY_BECAME_PRIMARY_SCN) FROM V$DATABASE; TO_CHAR(STANDBY_BECAME_PRIMARY_SCN) ---------------------------------------- SQL> alter session set nls_date_format='yyyy-mm-dd hh24:mi:ss'; Session altered. SQL> select oldest_flashback_scn,oldest_flashback_time from v$flashback_database_log; OLDEST_FLASHBACK_SCN OLDEST_FLASHBACK_TI -------------------- -------------------     1202090 2019-05-05 04:01:45 SQL> recover managed standby database cancel; Media recovery complete. SQL>  SQL>  SQL> recover managed standby database finish force; Media recovery complete. SQL> select database_role from v$database; DATABASE_ROLE ---------------- PHYSICAL STANDBY SQL> select open_mode,database_role,protection_mode,protection_level,switchover_status from v$database; OPEN_MODE     DATABASE_ROLE    PROTECTION_MODE   PROTECTION_LEVEL SWITCHOVER_STATUS -------------------- ---------------- -------------------- -------------------- -------------------- READ ONLY     PHYSICAL STANDBY MAXIMUM PERFORMANCE  MAXIMUM PERFORMANCE TO PRIMARY SQL> alter database commit to switchover to primary; Database altered SQL>  SQL> select open_mode,database_role,protection_mode,protection_level,switchover_status from v$database; OPEN_MODE     DATABASE_ROLE    PROTECTION_MODE   PROTECTION_LEVEL SWITCHOVER_STATUS -------------------- ---------------- -------------------- -------------------- -------------------- MOUNTED     PRIMARY      MAXIMUM PERFORMANCE  UNPROTECTED NOT ALLOWED SQL> SELECT TO_CHAR(STANDBY_BECAME_PRIMARY_SCN) FROM V$DATABASE; TO_CHAR(STANDBY_BECAME_PRIMARY_SCN) ---------------------------------------- 1330559 SQL> alter database open; Database altered. SQL> select open_mode,database_role,protection_mode,protection_level,switchover_status from v$database; OPEN_MODE     DATABASE_ROLE    PROTECTION_MODE   PROTECTION_LEVEL SWITCHOVER_STATUS -------------------- ---------------- -------------------- -------------------- -------------------- READ WRITE     PRIMARY      MAXIMUM PERFORMANCE  MAXIMUM PERFORMANCE NOT ALLOWED SQL> SELECT TO_CHAR(STANDBY_BECAME_PRIMARY_SCN) FROM V$DATABASE; TO_CHAR(STANDBY_BECAME_PRIMARY_SCN) ---------------------------------------- 1330559 SQL>