Re: [Firebird-devel] RFC: Timeouts

[Leyne, S. <Se...@br...>]

> > ---------------
> >    The feature could be useful for:
> > - database administrators get instrument to limit heavy queries from
> >    consuming too much resources
> 
> The problem is that long running transactions does not always equate to
> "heavy queries".
> 
> (1) A NATURAL SELECT which returns 1M rows that a client fetches over 120
> minutes is completely different from (2) a SELECT that executes for 120
> minutes and returns nothing (cus the SELECT is invalid/badly constructed)
> 
> While the long transaction time of (1) does have a 'cost' when it comes to
> garbage collection, etc.
> 
> From an operational perspective, IMO, it is cases like (2) which are more important to catch.

I don't know what happened but the line above was showed as quoted from Vlad posts, that was not the case.  

The last part of my post should have read:


>From an operational perspective, IMO, it is cases like (2) which are more important to catch.

Why more?

Because (2) is entirely consuming a single CPU, likely creating a significant amount of disk IOs and thus is having a direct impact on the performance of other connections.