先备份一下 C:\oracle\product\10.2.0\db_2\dbs  
SPFILEIDMP.ORA
alter system set open_cursors=600 scope=spfile;
500 ~1000   
 select a.name, b.value
 from v$statname a, v$mystat b
 where a.statistic# = b.statistic#
and lower(a.name) like '%' || lower('cursor')||'%'
NAME                                                                  VALUE
---------------------------------------------------------------- ----------
opened cursors cumulative                                               166
opened cursors current                                                    1
session cursor cache hits                                               107
session cursor cache count                                               19
cursor authentications                                                   18
参考
http://hi.baidu.com/xiutuo/blog/item/db64e27e5b72233c0dd7da0a.html
http://blog.chinaunix.net/u2/68465/showart_683669.html
http://lovexueer.itpub.net/post/5072/45405