SYBASE在DUMP后，占用的系统缓存不释放，为什么要删除这个备份文件后才释放？

梨花院

如题！
谢谢！

1017of

OS version?AIX?

梨花院

原帖由 1017of 于 2007-4-11 10:25 发表
OS version?AIX?

ASE 12.5  win2003

小无赖

占用的系统缓存不释放是什么意思?

梨花院

原帖由 小无赖 于 2007-4-11 11:56 发表
占用的系统缓存不释放是什么意思?

就是执行完DUMP数据备份后，占用的系统缓存不是释放，而容量大小差不多是这个导出的文件容量，差不多是300M！

小无赖

是在任务管理器中看的吗?哪个进程占用了300M内存?

1017of

share this url with you
http://www.microsoft.com/technet ... cache.mspx?mfr=true

梨花院

原帖由 小无赖 于 2007-4-11 16:07 发表
是在任务管理器中看的吗?哪个进程占用了300M内存?

任务管理器看不到有这样的进程！
主要是导出数据后，缓存占*.bck这个文件大小没有释放，一定要删除后，系统缓存才释放！

梨花院

原帖由 1017of 于 2007-4-11 16:20 发表
share this url with you
http://www.microsoft.com/technet ... cache.mspx?mfr=true

这个是解释！
并没有说为什么SYBASE备份后，缓存不释放？

1017of

I just looked over it roughly.as we known,SYBASE will read pages with useful data and dump them into dump device,a file in your case.according to the article,"the Virtual Memory Manager could map entire file into system cache.this increases the likelihood that data requested will be found there."so I guess the dumped file could be mapped into system cache,do you agree with that?
pls pay attention to the segment of page flushing."Two threads in the system process—the lazy writer thread and the mapped page writer thread—periodically flush unused pages to disk.The cache is also flushed when Virtual Memory Manager needs to shrink the cache because of memory constraints."it seems the system processes control the flushing actions. but when to do and how to do are still our questions.unfortunately,I did not find the answer from from this topic.maybe we need to find more information to open our mind.