设置sga和pga的值

--设置sga的值
1)alter system set sga_max_size=256m scope=spfile; &&写入SPFILE,重启生效
2)alter system set sga_max_size=256m scope=memory; &&写入内存区,立即生效
3)alter system set sga_max_size=256m scope=both; &&即写入内存区,又写入SPFILE,默认为BOTH
--设置pga的值
1)alter system set pga_aggregate_target=10G;
2)alter system set sga_target=8G sid='fyweb' scope=both;