修改Memory_max_target为0出错

最新推荐文章于 2025-06-10 23:45:49 发布

原创最新推荐文章于 2025-06-10 23:45:49 发布 · 5.1k 阅读

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本文详细介绍了在尝试使用ALTER SYSTEM命令设置SGA_TARGET时出现的错误，包括ORA-00843和ORA-00849错误，并提供了解决这些问题的方法，包括创建PFILE文件、修改SPFILE文件以及启动实例的步骤。

SQL> connect / as sysdba
Connected.
SQL> alter system set memory_target=0;

System altered.
SQL> alter system set memory_max_target=0;
alter system set memory_max_target=0
*
ERROR at line 1:
ORA-02095: specified initialization parameter cannot be modified

SQL> alter system set memory_max_target=0 scope=spfile; --

System altered.

SQL> alter system set sga_target=6G scope=spfile;

System altered.

SQL> alter system set pga_aggregate_target=2112M;

System altered.

SQL> alter system set shared_pool_size=0;

System altered.

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORA-00843: Parameter not taking MEMORY_MAX_TARGET into account
ORA-00849: SGA_TARGET 6442450944 cannot be set to more than MEMORY_MAX_TARGET 0.
SQL> startup nomount
ORA-00843: Parameter not taking MEMORY_MAX_TARGET into account
ORA-00849: SGA_TARGET 6442450944 cannot be set to more than MEMORY_MAX_TARGET 0.

解决方法：

Symptoms

When trying to set SGA_TARGET using an ALTER SYSTEM command, the following errors are raised:

ORA-00843: Parameter not taking MEMORY_MAX_TARGET into account

ORA-00849: SGA_TARGET 10737418240 cannot be set to more than MEMORY_MAX_TARGET 0.

Changes

MEMORY_MAX_TARGET was set to 0.

Cause

The problem is caused by the MEMORY_MAX_TARGET parameter explicitly being set to 0. In case AMM should not be used, MEMORY_MAX_TARGET should not be set at all.

Solution

The solutions to the problem are:

create a PFILE from the SPFILE being used and remove the MEMORY_MAX_TARGET=0 and MEMORY_TARGET=0 lines. After that, use the modified PFILE to create a new SPFILE and start the instance with this new setup.
[oracle@bakdbserver dbs]$ vi initbakdb.ora
SPFILE='+DATA/bakdb/spfilebakdb.ora'
memory_max_target=21G
memory_target=21G

[oracle@bakdbserver dbs]$ sqlplus "/as sysdba"
SQL> startup
should the instance be running, then use the following commands to remove the explicit setting of MEMORY_TARGET=0 and MEMORY_MAX_TARGET=0:

alter system reset memory_target; alter system reset memory_max_target; [oracle@bakdbserver dbs]$ vi initbakdb.ora SPFILE='+DATA/bakdb/spfilebakdb.ora' #memory_max_target=21G #memory_target=21G [oracle@bakdbserver dbs]$ sqlplus "/as sysdba" SQL> startup force