我用sql切换dg保护模式，主备查询保护模式都没问题：
SQL> alter database set standby database to maximize availability;
Database altered.
SQL> select name,open_mode,protection_mode from v$database;
NAME OPEN_MODE PROTECTION_MODE
--------- -------------------- --------------------
WYZC READ WRITE MAXIMUM AVAILABILITY
但用dgbroker查缺有这样的错误：
DGMGRL> show configuration;
Configuration - dgwyzc
Protection Mode: MaxPerformance
Databases:
wyzc - Primary database
Error: ORA-16628: broker protection mode inconsistent with the database setting
swyzc - Physical standby database
Fast-Start Failover: DISABLED
Configuration Status:
ERROR
这是什么原因呢？