Re: Oracle7 multithreaded server

In article <1607100004_at_igc.apc.org>, rfinkelstein_at_igc.apc.org (Richard Finkelstein) writes:
|>
|> AS I understand the Oracle architecture, it is not a single process/multi-
|> threaded architecture. The database servers are still pretty much the same
|> as Oracle 6, but there is a new dispatcher architecture which helps reduce
|> memory requirements. It is not clear whether there is any performance
|> advantage with this architecture. I have heard mixed comments.

Yes and no... It is not necessarily single process. The DBA can specify the number of servers to be started automatically and the maximum number of servers allowed per instance. The dispatcher determines which server is a likely candidate for the connection request.

This means that it could indeed be single process, by specifying the maximum number of servers as 1. The intention though, is that a suitable number of servers is started when the instance is brought up and that Oracle itself will determine whether to add more depending on loading, up to the maximum....

The advantage of the multi-threaded server comes in the Unix two-task environment. As opposed to one shadow process per process, it is now determined by an optimal/maximum number of shadow processes (servers) per process. If you attempt to run it under VMS, for example, it will slow down dramatically!

|>
|> This new dispatching mechanism does require SQL*NET 2.0, which I understand is
|> still in beta and I have not heard of any announced production release date.

Yes; but I have had no serious problems with it under HP-UX 9, although I believe that this is not true of all platforms.

|>
|> Hope this helps.
|>
|> -- Rich
 

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