该客户的数据库是Oracle 11.1.0.7，运行在p550主机上，16个逻辑CPU，16G内存，AIX 6.1 位系统，共分配了8G内存给SGA，2G内存给

昨天去一客户那里做巡检，遇到了经典的ora-04030错误，alert日志如下：

Tue Oct 28 09:57:46 2014
Errors in file /Oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/trace/wmsdb_ora_33358038.trc (incident=177302):
ORA-04030: out of process memory when trying to allocate 118808 bytes (QERHJ hash-joi,kllcqas:kllsltba)
Incident details in: /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/incident/incdir_177302/wmsdb_ora_33358038_i177302.trc
Errors in file /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/trace/wmsdb_ora_33358038.trc (incident=177303):
ORA-04030: out of process memory when trying to allocate 169040 bytes (pga heap,kgh stack)
ORA-04030: out of process memory when trying to allocate 118808 bytes (QERHJ hash-joi,kllcqas:kllsltba)
Incident details in: /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/incident/incdir_177303/wmsdb_ora_33358038_i177303.trc
Errors in file /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/incident/incdir_177302/wmsdb_ora_33358038_i177302.trc:
ORA-04030: out of process memory when trying to allocate 169040 bytes (pga heap,kgh stack)
ORA-04030: out of process memory when trying to allocate 118808 bytes (QERHJ hash-joi,kllcqas:kllsltba)
Errors in file /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/trace/wmsdb_ora_33358038.trc (incident=177304):
ORA-04030: out of process memory when trying to allocate 160 bytes (pga heap,control file cache)
ORA-04030: out of process memory when trying to allocate 118808 bytes (QERHJ hash-joi,kllcqas:kllsltba)
Incident details in: /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/incident/incdir_177304/wmsdb_ora_33358038_i177304.trc
Tue Oct 28 09:57:53 2014
Trace dumping is performing id=[cdmp_20141028095753]
Tue Oct 28 09:57:54 2014
Sweep Incident[177303]: completed
Tue Oct 28 09:57:57 2014
Errors in file /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/incident/incdir_177302/wmsdb_ora_33358038_i177302.trc:
ORA-04030: out of process memory when trying to allocate 160 bytes (pga heap,control file cache)
ORA-04030: out of process memory when trying to allocate 118808 bytes (QERHJ hash-joi,kllcqas:kllsltba)
Errors in file /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/trace/wmsdb_ora_33358038.trc (incident=177305):
ORA-04030: out of process memory when trying to allocate 16776728 bytes (QERHJ hash-joi,QERHJ Hash Table Entries)
Incident details in: /oracle/app/oracle/diag/rdbms/wmsdb/wmsdb/incident/incdir_177305/wmsdb_ora_33358038_i177305.trc
Trace dumping is performing id=[cdmp_20141028095802]
......

该客户的数据库是Oracle 11.1.0.7，运行在p550主机上，16个逻辑CPU，16G内存，AIX 6.1 位系统，共分配了8G内存给SGA，2G内存给PGA，由memory_target=10G参数动态调整，同时，memory_max_target也设置成10G，表示Oracle最多可以占用OS的内存为10G（物理内存的62.5%）。这2个参数是11g新增的，可以动态分配SGA和PGA，而在10g中仅只能通过设置sga_target来动态管理sga中的各内存组件，pga是要另外手动设置的。

SQL> show parameters target

NAME TYPE VALUE
------------------------------------ ---------------------- ------------------------------
archive_lag_target integer 0
db_flashback_retention_target integer 1440
fast_start_io_target integer 0
fast_start_mttr_target integer 0
memory_max_target big integer 10G
memory_target big integer 10G
pga_aggregate_target big integer 2G
sga_target big integer 8G

网上google了一下，很多关于ora-04030的错误的描述都大同小异，主要由以下几种：
A. 对于32 BIT系统，有SGA 1.7G
B. 某些OS系统本身也有一些内存参数
C. OS系统本身物理内存+Swap的

对于A，由于系统是 bit的，没有1.7G的；
对于B，用ulimit查看的结果为ulimited;
对于C，，OS本身的内存为16G，不过用topas查看，内存使用率已经为90%