Subject Re: [Firebird-Architect] Re: query-thread priority
Author Jim Starkey
Rommel Abesames wrote:

>I think the difference is the usage of I/O completion ports. A
>pre-emptive scheduler will interrupt a task repeatedly while
>cooperative scheduling combined with I/O completion ports will only
>interrupt a task when the task waits on an I/O call.
>This can explain why currently a long Firebird (SS) query can dominate
>the does not yield to other tasks while waiting for I/Os
>to complete. Of course an infinite loop with no I/O in a cooperative
>scheduling scheme will still tie up the server...but not heavy
>I/O...which dbmss are more subject to.
No, the problem with Firebird is that it is effectively singled
threaded. Vulcan addresses this problem.


Jim Starkey
Netfrastructure, Inc.
978 526-1376