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记录一次修改sga大小之后出现的一系列报错
修改了oracle的sga大小之后，遇到了一系列的报错。
00844和00851报错
SQL> startup;
ORA-00844: Parameter not taking MEMORY_TARGET into account
ORA-00851: SGA_MAX_SIZE 2147483648 cannot be set to more than MEM
SQL>
01078报错
SQL> startup;
ORA-01078: failure in processing system parameters
LRM-00109: could not open parameter file '/u01/app/oracle/product/11.2.4/db_1/dbs/inittest.ora'
一、修改过程
1.1 为什么我要修改sga大小
在测试的时候，插入大量数据发现30009错误，我以为是sga小导致的
SQL> insert into t select rownum from dual connect by level<=10000000;
insert into t select rownum from dual connect by level<=10000000
*
ERROR at line 1:
ORA-30009: Not enough memory for CONNECT BY operation
Elapsed: 00:00:13.51
SQL>
查看sga
SQL> show parameter sga;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
lock_sga boolean FALSE
pre_page_sga boolean FALSE
sga_max_size big integer 1584M
sga_target big integer 1G
SQL>
查看pga
SQL> show parameter pga
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
pga_aggregate_target big integer 0
SQL>
1.2 修改sga
更改sga
SQL> alter system set sga_max_size=2048M scope=spfile;
System altered.
Elapsed: 00:00:00.06
SQL>
1.3 报错1
关闭和启动数据库
SQL> shutdown
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL>
SQL> startup
ORA-00844: Parameter not taking MEMORY_TARGET into account
ORA-00851: SGA_MAX_SIZE 2147483648 cannot be set to more than MEMORY_TARGET 1660944384.
结果出错了。经过查找资料，发现11g新增了个参数MEMORY_TARGET，其大小等于PGA+SGA，当sga的大小大于MEMORY_TARGET就会报如上错误。
查看MEMORY_TARGET大小，发现大小为1584M，与sga不符。
SQL> show parameter memory_target;
NAME TYPE VALUE
------------------------------------ --------------------------------- ------------------------------
memory_target big integer 1584M
SQL>
修改spfile文件中的参数
sga_max_size=1653604352
启动数据库
SQL> startup nomount;
ORA-01078: failure in processing system parameters
LRM-00109: could not open parameter file '/u01/app/oracle/product/11.2.4/db_1/dbs/inittest.ora'
SQL>
1.4 报错2
启动后遇到了01078报错。解决办法如下：
将test（实例名）文件夹下的init.ora.xxx 文件复制到dbs目录下即可，复制后的名字按照之前报错的提示输入。
[oracle@localhost ~]$ cp /u01/app/oracle/admin/test/pfile/init.ora.922018114616 /u01/app/oracle/product/11.2.4/db_1/dbs/inittest.ora
启动数据库
SQL> startup;
ORACLE instance started.
Total System Global Area 1653518336 bytes
Fixed Size 2213896 bytes
Variable Size 956303352 bytes
Database Buffers 687865856 bytes
Redo Buffers 7135232 bytes
Database mounted.
Database opened.
SQL>
二、总结
归根结底还是对数据库原理不熟导致的，牢记memory_target值需为sga+pga内存的和。