今天客户说从数据库后台发现报错，具体如下：
Errors in file /Oracle/linuxidc/saptrace/diag/rdbms/linuxidc/linuxidc/incident/incdir_183218/linuxidc_j003_8103_i183218.trc:
ORA-04030: out of process memory when trying to allocate 1052696 bytes (pga heap,log read buffer)
ORA-07445: exception encountered: core dump [kgdsdst()+16] [SIGSEGV] [ADDR:0xFFFFFFFF7FFB4634] [PC:0x1081A1C90] [Address not mapped to object] []
在查看的时候，并没有发现有什么语句问题的，检查系统限制如下：
root@linuxidc # ulimit -a
core file size (blocks, -c) unlimited
data seg size (kbytes, -d) unlimited
file size (blocks, -f) unlimited
open files (-n) 256
pipe size (512 bytes, -p) 10
stack size (kbytes, -s) 8192
cpu time (seconds, -t) unlimited
max user processes (-u) 29995
virtual memory (kbytes, -v) unlimited
同时，报错中指出Address not mapped to object，可能存在没有足够的交换分区
紧接着，又有如下报错
Errors in file /oracle/linuxidc/saptrace/diag/rdbms/linuxidc/linuxidc/trace/linuxidc_psp0_27454.trc:
ORA-27300: OS system dependent operation:fork failed with status: 12
ORA-27301: OS failure message: Not enough space
ORA-27302: failure occurred at: skgpspawn3
根据官网的介绍如下：
Cause
This issue is mainly caused by lack of memory / swap. Checking the memory configuration on the server, we have found the following
综合分析，报了04030的错误，而下面又分别报了27302及27301的错误。根据报错的意思，一方面，创建会话失败，另一方面，无法找到映射地址，所以怀疑与交换分区有关
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在CentOS 6.4下安装Oracle 11gR2(x64)
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该数据库是安装在solaris11上面的，检查如下：
root@linuxidc # swap -h -l
swapfile dev swaplo blocks free
/dev/zvol/dsk/rpool/swap 285,2 8K 4.0G 4.0G
交换分区只有4g，而物理内存有40g，显然过小，应该是由于这个问题引起的
解决办法就是扩展交换分区，solaris11的调整方法发生了变化，不同以前的版本
root@linuxidc:~# zfs set volsize=30g rpool/swap
检查调整结果：
root@linuxidc # swap -h -l
swapfile dev swaplo blocks free
/dev/zvol/dsk/rpool/swap 285,2 8K 4.0G 4.0G
/dev/zvol/dsk/rpool/swap 285,2 4.0G 26G 26G
调整完成后，叫继续跟踪，结果几个星期过去后，再也没有报错！