Re: Support Parallel Query Execution in Executor

"Joshua D. Drake" <jd(at)commandprompt(dot)com> writes:

> Well I am go out on a limb here and gather to guess that sequential scans and
> index scans are still very relevant because the CPU could be bound by the scan
> (either one) based on the type of query being performed.
>
> This doesn't really have anything to do with being IO bound as to the type of
> accesses to the data we have to deal with in regards to query processing.

It has everything to do with being i/o bound. The only way having two
processors perform part of an index or sequential scan would help is if your
disk subsystem is capable of providing data faster than a single processor is
capable of requesting it.

That's only going to be true for very high end systems with multiple raid
controllers and dozens of spindles.

On the other hand even moderately sized dual-core systems could probably
benefit from being able to perform multiple cpu-intensive operations
simultaneously.

--
greg