Re: Cache Hit Ratio from system views

On Aug 28, 12:02 am, "fitzjarr..._at_cox.net" <fitzjarr..._at_cox.net> wrote:
> On Aug 26, 6:13 pm, "Bob Jones" <em..._at_me.not> wrote:
>
>
>
> > "Richard Foote" <richard.fo..._at_nospam.bigpond.com> wrote in message
>
> >news:2_Wyi.24466$4A1.1328_at_news-server.bigpond.net.au...
>
> > > "Bob Jones" <em..._at_me.not> wrote in message
> > >news:kOtyi.50198$YL5.8637_at_newssvr29.news.prodigy.net...
>
> > >> High BCHR is always better than low - provided everything else being
> > >> equal. If BCHR is useless for the stated reasons, no other indicator
> > >> would be useful.
>
> > > This I'm afraid is where you're fundamentally incorrect.
>
> > > A high BCHR can mean your database is on life support, struggling to cope
> > > with exessive LIOs due to inefficient SQL with users staring at an
> > > hourglass rather than returned data.
>
> > > A BCHR that has increased can mean your database has suddenly hit
> > > significant performance issues. Or it can mean things have improved. Or it
> > > can mean response times remain unaffected.
>
> > > A BCHR that has reduced can mean your database has suddenly hit
> > > significant performance issues. Or it can mean things have improved (yes,
> > > improved because that crippling transaction that was previously performing
> > > poorly due to massively exessive LIOs has been fixed, reducing the overall
> > > BCHR) . Or it can mean response times remain unaffected.
>
> > > Not much of an indicator is it ?
>
> > > But saying that a BCHR is *always* better than a low is just plain wrong
> > > wrong wrong ...
>
> > Didn't I repeatedly say "provided everything else being equal"?
>
> > > Do yourself a favour and read this
> > >www.hotsos.com/e-library/abstract.php?id=6?
>
> > Do yourself a favor and read my comments correctly.- Hide quoted text -
>
> > - Show quoted text -
>
> We have 'read your comments correctly' and still we arrive at the same
> conclusion with respect to your 'reasoning' and 'logic'. Your
> criteria that 'everything else being equal' means what, exactly? What
> is 'everything else', and how do you define 'equal'? You're spouting
> verbiage which means little, and that does nothing to fuel your
> argument. Howard and Richard have provided much in the way of
> information against your contentions, and have proven their points
> unequivocably. You, on the other hand, have proven nothing except
> that you apparently love to see your responses in print, whether or
> not they are sensible.
>
> You need to re-read Howard's and Richard's responses again. And
> again. And yet again. Possibly you'll reach an understanding that
> your original points of contention are ill-conceived and you'll have
> learned something.
>
> David Fitzjarrell

Nah, he won't.

If he was interested in learning something, he'd have taken something on board by now. At the very least, he would be *arguing* the point with facts, logic, reason, instead of merely asserting things oblivious to, or in blunt and un-addressed conflict with, the points made by others. When something is so apparently a matter of blind faith, there's no learning going on, and there's none going to go on.

The thread is useful, nonetheless, for anyone that might come after. A high BCHR can mean bad news; a low one good news. Contention will "improve" the BCHR; improving your SQL so it does less work will "worsen" it; 'everything else being equal' is a phrase devoid of any meaning in this context... these are good things for others to absorb, I think.

But "Mr Jones" is a lost cause, a closed mind and someone best left to indulge in his own misconceptions as he pleases. Received on Tue Aug 28 2007 - 00:04:21 CDT