maximum protection 转 maximum availability

PS：该实验建立在之前DG博客的基础之上的

主库之前的状态，执行转换语句，主库之后的状态

1. 15:00:01 SYS @ slow >select name,database_role,protection_mode from v$database;
   
3. NAME     DATABASE_ROLE PROTECTION_MODE
4. ——— —————- ——————–
5. SLOW     PRIMARY     MAXIMUM PROTECTION
7. 1 row selected.
9. Elapsed: 00:00:00.00
10. 15:00:35 SYS @ slow >select status from v$instance;
12. STATUS
13. ————
14. OPEN
16. 1 row selected.
18. Elapsed: 00:00:00.00
19. 18:57:24 SYS @ slow >startup mount force;
20. ORACLE instance started.
22. Total System Global Area 521936896 bytes
23. Fixed Size         2254824 bytes
24. Variable Size         377489432 bytes
25. Database Buffers     138412032 bytes
26. Redo Buffers         3780608 bytes
27. Database mounted.
28. 18:57:44 SYS @ slow >select name,database_role,protection_mode from v$database;
30. NAME     DATABASE_ROLE PROTECTION_MODE
31. ——— —————- ——————–
32. SLOW     PRIMARY     MAXIMUM PROTECTION
34. 1 row selected.
36. Elapsed: 00:00:00.01
37. 18:58:20 SYS @ slow >select status from v$instance;
39. STATUS
40. ————
41. MOUNTED
43. 1 row selected.
45. Elapsed: 00:00:00.01
46. 18:58:39 SYS @ slow >alter database set standby database to maximize availability;
48. Database altered.
50. Elapsed: 00:00:00.00
51. 19:00:09 SYS @ slow >alter database open;
53. Database altered.
55. Elapsed: 00:00:03.03
56. 19:00:25 SYS @ slow >select name,database_role,protection_mode from v$database;
58. NAME     DATABASE_ROLE PROTECTION_MODE
59. ——— —————- ——————–
60. SLOW     PRIMARY     MAXIMUM AVAILABILITY
62. 1 row selected.
64. Elapsed: 00:00:00.00
65. 19:01:20 SYS @ slow >

备库之前的状态，主库执行转换语句，备库之后的状态  ，，，一切正常，转换成功！！！

1. 14:56:33 SYS @ gotime >select name,database_role,protection_mode from v$database;
   
3. NAME     DATABASE_ROLE PROTECTION_MODE
4. ——— —————- ——————–
5. SLOW     PHYSICAL STANDBY MAXIMUM PROTECTION
7. 1 row selected.
9. Elapsed: 00:00:00.00
10. 14:57:21 SYS @ gotime >select status from v$instance;
12. STATUS
13. ————
14. OPEN
16. 1 row selected.
18. Elapsed: 00:00:00.00
19. 18:56:45 SYS @ gotime >startup mount force;
20. ORACLE instance started.
22. Total System Global Area 521936896 bytes
23. Fixed Size         2254824 bytes
24. Variable Size         377489432 bytes
25. Database Buffers     138412032 bytes
26. Redo Buffers         3780608 bytes
27. Database mounted.
28. 18:57:07 SYS @ gotime >select name,database_role,protection_mode from v$database;
30. NAME     DATABASE_ROLE PROTECTION_MODE
31. ——— —————- ——————–
32. SLOW     PHYSICAL STANDBY MAXIMUM AVAILABILITY
34. 1 row selected.
36. Elapsed: 00:00:00.04
37. 19:02:08 SYS @ gotime >