SGA_MAX_SIZE超过MEMORY_TARGET 导致无法启动

SQL> startup mount

\ORA-00844: Parameter not taking MEMORY_TARGET into account

ORA-00851: SGA_MAX_SIZE 3154116608 cannot be set to more than MEMORY_TARGET 1526726656.

DB再启动数据库的时候报SGA_MAX_SIZE超过MEMORY_TARGET，经查发现设置oracle.install.db.config.starterdb.memoryLimit=3000，然而SGA_MAX_SIZE 设置的值大于这个值，所以导致无法启动！！！！

这个DB居然实先木有生成pfile文件，好吧我来讲讲恢复方法

恢复pfile

SQL> create pfile='/opt/app/init.ora' from spfile;

File created.

赶紧修改pfile的 SGA_MAX_SIZE 值

然后再恢复数据库

SQL> startup nomount pfile='/opt/app/init.ora';

ORACLE instance started.

Total System Global Area 1068937216 bytes

Fixed Size 2260088 bytes

Variable Size 310379400 bytes

Database Buffers 750780416 bytes

Redo Buffers 5517312 bytes

SQL> alter database mount;

Database altered.

SQL> create spfile from pfile='/opt/app/init.ora';

File created.

SQL> alter database open;

Database altered.

现在要记得创建pfile

SQL> create pfile from spfile;

File created.