https://community.hpe.com/t5/openvms/reserved-memory/m-p/2247971#M141 若您不介意 database start 的時候 create SGA 多花一些時間, 且 SGA 不太會 extend, 可不用 reserved memory.<BR /><BR /><BR /><BR />如其名, "reserved memory" 是 vms 在開機時便預留下來的連續位置 (os 可先建好 global page table entries, initialized all zero). 您可開機時先 reserve 1GB memory, 而 SGA 只用 512MB, 剩下的備不時之需. 缺點是平時有 512MB 不能作其他用途. <BR /><BR /><BR /><BR />第一次 create "reserved memory" 或 更改 "reserved memory" 的大小時, 必須記得執行 autogen/feedback, autogen 會將 "reserved memory" 的大小考慮進去.<BR /><BR /><BR /><BR />Oracle maunal 建議用"reserved memory" , 好處如下<BR /><BR /><BR /><BR />The advantages to reserving memory for an SGA are as follows:<BR /><BR />■ You can be certain that the memory is available and that the system is correctly tuned.<BR /><BR />■ The memory is reserved at boot time as contiguous aligned physical pages. This allows the system to optimize the mapping of the SGA.<BR /><BR />■ The memory is pre-allocated and zeroed. This results in faster SGA mapping and faster instance startup.<BR /><BR /><BR /><BR /> <BR /><BR /> Tue, 21 Sep 2004 23:16:36 GMT watermelonyu 2004-09-21T23:16:36Z https://community.hpe.com/t5/openvms/reserved-memory/m-p/2247970#M140 oracle 9i on vms 的installation guide步驟有寫到reserved memory的使用<BR /><BR />但是在database start的時候就已經會去create 一塊SGA了<BR /><BR />假設我的db 都可以正常啟動,我還需要reserved memory嗎<BR /><BR />請問實際運用上,你們會建議使用reserved memory嗎?<BR /><BR /> Mon, 20 Sep 2004 23:36:24 GMT https://community.hpe.com/t5/openvms/reserved-memory/m-p/2247970#M140 watermelonyu 2004-09-20T23:36:24Z https://community.hpe.com/t5/openvms/reserved-memory/m-p/2247971#M141 若您不介意 database start 的時候 create SGA 多花一些時間, 且 SGA 不太會 extend, 可不用 reserved memory.<BR /><BR /><BR /><BR />如其名, "reserved memory" 是 vms 在開機時便預留下來的連續位置 (os 可先建好 global page table entries, initialized all zero). 您可開機時先 reserve 1GB memory, 而 SGA 只用 512MB, 剩下的備不時之需. 缺點是平時有 512MB 不能作其他用途. <BR /><BR /><BR /><BR />第一次 create "reserved memory" 或 更改 "reserved memory" 的大小時, 必須記得執行 autogen/feedback, autogen 會將 "reserved memory" 的大小考慮進去.<BR /><BR /><BR /><BR />Oracle maunal 建議用"reserved memory" , 好處如下<BR /><BR /><BR /><BR />The advantages to reserving memory for an SGA are as follows:<BR /><BR />■ You can be certain that the memory is available and that the system is correctly tuned.<BR /><BR />■ The memory is reserved at boot time as contiguous aligned physical pages. This allows the system to optimize the mapping of the SGA.<BR /><BR />■ The memory is pre-allocated and zeroed. This results in faster SGA mapping and faster instance startup.<BR /><BR /><BR /><BR /> <BR /><BR /> Tue, 21 Sep 2004 23:16:36 GMT https://community.hpe.com/t5/openvms/reserved-memory/m-p/2247971#M141 watermelonyu 2004-09-21T23:16:36Z https://community.hpe.com/t5/openvms/reserved-memory/m-p/2247972#M142 reserved memory如果有用到Swap的話<BR /><BR />個人覺得應該就要考慮一下了吧<BR /><BR />我的經驗裡是<BR /><BR />AP用了最多的reserved memory(應該是oracle fork出來的)<BR /><BR />真搞不懂在作啥... Sat, 25 Jun 2005 09:52:04 GMT https://community.hpe.com/t5/openvms/reserved-memory/m-p/2247972#M142 watermelonyu 2005-06-25T09:52:04Z