Re: [Sqlgrey-users] Performance: strict versus loose expiration time

[Michael S. <Mic...@lr...>]

On Wed, 28 Feb 2007, Lionel Bouton wrote:

> Michael Storz wrote the following on 22.02.2007 10:16 :
> > Hi Dan and Lionel,
> >
> > the last days I was thinking about the performance impact of implementing
> > a strict versus a loose expiration time. At the moment, Sqlgrey uses a
> > mixed implementation, the is_in_* subroutines use a strict implementation,
> > whereas the count subroutines use a loose implementation.
> >
> > strict means, every select has a condition in the where-clause which
> > results in returning only active entries from a table.
> >
> > loose means, there is no such condition in the where-clause. Expiration is
> > handled only by deleting expired entries from a table via a cleanup
> > subroutine.
> >
>
> strict seems better to me. It didn't seem to matter much when I coded
> the loose count subroutines, but looking back on the code I don't like
> the fact that db_cleandelay has an impact on the auto-whitelist behaviour.
>
> I vote for the "strict" behaviour.
>
> Lionel
>

How about this: I think, I would able to deliver a patch which decides at
compile/parse-time if a loose or strict implementation will be used (this
means code for the other possibility will be eliminated at parse time).
This could be triggered by a commandline flag. Default would be strict.
But before I'll do this I have to test if there is any noticeable speed
advantage of having a loose implementation (and this needs some time).

Michael Storz
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