Subject Re: [firebird-support] How to change cpu utilization in Firebird engine?
Author Ann Harrison
On Thu, Jan 5, 2017 at 9:54 PM, trskopo@... [firebird-support] <> wrote:

As you know, on a single connection, Firebird's cpu utilization calculate by 100% / no of cores.

That's not an arbitrary limit.  Firebird is not capable of running a single connection on multiple threads, 
and a single thread runs only on a single core.  Firebird 3 in SuperServer mode can run different
connections on different threads - a great step forward! - but when there is a single connection it
runs on a single thread.  Prior to V3, the only way you could use multiple cores was to run Firebird
in Classic or Super Classic mode.

On my 6 cores cpus, its only utilized 100% / 6 = 16%.

Right.  That's the way it is. 

During database maintenance & testing (backup, restore, testing, etc) , sometimes, i feel it was to slow.

You could try classic, but I suspect that you're running a single connection which cannot be run on more than one core. 

I want to change cpu utilization only for my own use. I have downloaded Firebird source code, please help me to point out which codes I should change & if my knowledge is enough is I only have basic C?

The Firebird group does not impose the "single core per connection" limit arbitrarily just to annoy users.  Breaking a query up so it runs on multiple cores is a hard problem, so I doubt very much that someone with basic C skills and little background in developing database managers would have much success implementing it.

Good luck,