Re: High numbers of buffer waits in OnLine

In article <4rbdis$t64@news.eunet.cz>, Miroslav Lorenc <mirek@sasik.traveller.cz> writes >David Williams (djw@smooth1.demon.co.uk) wrote: > >: If you are getting many bugger waits then increase the number of >: buffers. Ignore the caching percentages, just add more buffers. >: PS This worked for me. >: -- >: David Williams > >Buffer wait means that process is waiting for the buffer used by some other >process. Process is waiting because it needs to work with the particular >page stored in this buffer. It is similar to lock wait - concurrency problem. >So I think increasing the number of buffers will not help. Try to check >application logic or data model, if it is a real problem for your client. > >Regards > >-- > Miroslav Lorenc > >Software Applications and Systems E-mail: Miroslav.Lorenc@sasprg.cz >Prague >Czech Republic First apologies for the typo above - f and g are next to one another on the keyboard! Buffer wait does mean that the process is waiting for a buffer which is in use by another process. However they do not have to be accessing the same data. What if you want to read in a page from disk and all the buffers are already in use? i.e. the page is not already in the buffers but all the buffers are in use so you have to wait for a buffer to become free. This was one of the few questions I raised when I went on the OnLine Performance Tuning course last June. -- David Williams