Archive for June 2nd, 2008
关于PGA的大小
Monday, June 2nd, 2008
前几天MSN上有个朋友的数据库PGA设置了4G，忽然整个os里，PGA占了10多个G。这个问题我一直耿耿于怀，记得Donny曾经说过，今天终于在聊天记录找到了。
“In the latest release 10.2 Oracle changed these default values. The memory allocated to a single SQL operator (_smm_max_size) is limited to:
for P_A_T <= 500MB the parameter _smm_max_size = 20% of P_A_T
for P_A_T between 500MB and 1000MB the parameter _smm_max_size = 100M
for P_A_T betweeen 1001MB and 2560MB (2.5GB) the parameter _smm_max_size = 10% of P_A_T
for [...]
