Re: Is a Multithreaded Ingres On the Horizon???

Regarding Sybase's restriction, which he describes, to one DB engine per CPU: dshapiro_at_apple.com (David Shapiro) writes:

>This means there will be queries stuck in the swapped out engine while the
>other engines work on their tasks. It seems that it would be better as
>Sybase has restricted it, since having the extra engine is only creating
>more work for the OS, and not allowing any more database througput. Other
>database vendors argue that the extra engines allow one to prioritize
>queries as the database scheduler sees them (whereby one sets the OS
>priority of the engines, so some engines get more cpu time than others.)
>This may work under architectures such as Ingres or Oracle, where I believe
>the clients can direct their queries to a specific engine, but this would
>only hinder Sybase's throughput because a low priority engine with a long
>running query would only hold locks longer and reduce througput. Plus, the
>clients cannot pick a specific engine to process their query (hence the
>'virtual' name?)

With Ingres -- I don't know about others -- you can restrict DB engines to connect to only specified databases. Thus if work with DBx is considered much higher priority than work with DBy, the engine process that serves queries to DBx could be given higher OS priority than the engine process that serves DBy, with both these servers running on the same CPU.

                                Seth Received on Thu Aug 19 1993 - 09:19:05 CEST