SEQUENCE tracking

Hi all !

I have the following problem :
Many processes/threads write into a common table, that I use as a messaging queue. I use sequences, and that way the writers don't block each other.

I also have many readers. The readers should be able to read all the entries that they didn't read before.

How can I accomplish that ?
To those of you that don't understand the problem : if the reader reads messages 1,2,3,4,6,7,8 it can't assume that messages # 5 will never be written.
It might be in the process of writing.
I also don't want to add any locks to this scheme. The readers should read only the new committed messages, and the writers should be able to write without being blocked.

Any ideas ?

Eran Received on Sun Mar 24 2002 - 11:04:53 CET