????3. Linux ?o??????????
????kernel.shmmax ----
????Shmmax ????????????????????????????嵥?????????ε?????shmmax ????????????????????????????????????????SGA ?????????????????????????????????Σ?????????????????????? ??
???????????Щ????? SHMMAX ??????????????α???????????????????????????????????α????????(Process)????????????????????????????ε??????shmmax ??? ????????????????????????????????????????????????????????????????????? ?????????????????θ???????????????????????????????????????????
????Steve Adams ??????С??????????????????????Server Process ????????????С????????ο?????μ?????????????????(?????????? ??????????????????Σ????????????????y???????ν???“???”???????Щ???)??????????????????????????ζ????????????????Create Processes?????Destroy Them??????????治??????????
???????Oralce ?????????????????????????????????SGA?????????κ????
????????????????????????????????????
????Oracle ?????????? 32Bit Linux ??????shmmax ?32Bit ????????
????(setting shmmax to the 32-bit number limit)?????4G ??
????????????????1-4G ????????棬???????????shmmax ?????????漴??????SGA ?????????????????У?32Bit Linux ????????????4G ???????4G ???? ??
????????????????shmmax >=SGA (32Bit ?????????1.7G ????SGA ??????) ???????64Bit ??Linux ????????shmmax ?????????SGA_MAX_SIZE ???ɡ? (?????ο?)
????Ipcs  -sa ??????????????θ???
????kernel.shmall ----
????kernel.shmall ?????????????????? ??Linux ??????????С?4KB?? ???????ε??С?????????????С????????????????????ε???С??16G???????????????????? 16GB/4KB=16777216KB/4KB=4194304 ??????????64Bit ????16GB ??????棬???? kernel.shmall = 4194304 ????????(?????????????2097152??????)??????????shmmax ?????????? 16G ????????????SGA_MAX_SIZE ??SGA_TARGET ? 12G???????????SGA ???С????????????2G~14G ??????Э??PGA??????OS ??????????????????????????????16G????
????kernel.shmmni ----
????shmmni ??????????????ε?????????????????????? shmmin????shmmni?? shmmin ???????С??С ?? ??shmmni ??? 4096 ?????????????? ??
????3. Oracle ????????????????
????SGA_MAX_SIZE
????SGA_TARGET
????DB_CACHE_SIZE
????SGA_MAX_SZIE ????????????sga ????????????????????????????SGA_TARGET ?10g ?????sga ???????????????????????????????.sga_max_size ?? SGA ???????С????????? sga_max_size С??????SGA ?и???pool ?????????С?????sga_max_size ?????oracle ?????????SGA ????????檔?????????sga_max_size ??oracle ?????????????SGA ????????????sga_max_size ????????? sga_max_size ????????SGA ?и???pool ???????????????sga_max_size ???????????п?????????????????????????????sga_max_size?????????pfile ?е?sga_max_size ??????????????
??????Oracle 10g ????????????????????????SGA_TARGET???????Oracle 10g??????????????????????????Automatic Shared Memory Management ASMM??????????????????????????????SGA_TARGE????????????????????????????????????С???SGA_TARGET ?????SGA ?????????????С????SGA ?и????????С??Oracle ???п?????????????????Oracle ????????????????????С???????????????????????С??????????????????SGA_TARGET ???????????????SGA_TARGET ??????????0??????????ASMM????????????ASMM?????
????10g??11g ?????? SGA_TARGET ??????ASSM ??????? ??????μ???Щ????????С???
??????????????
????* Buffer cache (DB_CACHE_SIZE)
????* Shared pool (SHARED_POOL_SIZE)
????* Large pool (LARGE_POOL_SIZE)
????* Java pool (JAVA_POOL_SIZE)
????* Streams pool (STREAMS_POOL_SIZE)
??????SGA ?е??????????????С???????????????????????SGA_MAX_SIZE ???????????SGA ????С??????????????????????????????С???????SGA_MAX_SIZE ???С??Oracle10g ?￡? SGA_MAX_SIZE ??????SGA ???С???????????SGA_TARGET ??SGA ????????????С????????????SGA_TARGET< SGA_MAX_SIZE ?????oracle?????SGA_MAX_SIZE ?????SGA_TARGET ?????SGA ?????????е??????????????????С??????????????SGA_MAX_SIZE ?????
???????????????????飬???Щ?汾?У??????????汾????汾??????SGA_TARGET< SGA_MAX_SIZE ?????????????SGA_MAX_SIZE ???SGA_TARGET ???С???
??????11g ?У????SGA_TARGET ????????????SGA_MAX_SIZE ???С??????????С??oracle ??????????????????????????????????????????????oracle??SGA_TARGET ???С???????????????????????С?
????SGA_TARGET ????????????????????SGA ????????????????????????????ASMM ?????Oracle ??????????????????????????С???????????Щ??????????????Щ?????????????е?ì??????????