On Fri, Oct 8, 2010 at 12:07 PM, Cesar Inacio Martins <
cesar_inacio_martins (AT) yahoo (DOT) com.br> wrote:
Quote:
Hi,
By default the IFX_FOLDVIEW is disabled .
I read in some places of the documentation about the vantages to active
this option. But no disvantages are mentioned... or risks of degrade the
performance when enable it, or others consequences (problem with triggers?
permission?)
So, anyone can explain to me , why not keep this option enabled by default
?
I don't see any disadvantage. But this raises the question: Why the hell
|
does the parameter exist?
My *personal* opinion on this is that this and other parameters exist
because R&D cannot be 110% sure that the new behavior will not be bad at
times. So the parameter allows the engine to fallback to the "old" behavior.
I recall having hit a bug with this activated but it was on the first
fixpack where it was introduced.
There are other parameters that follow the same idea: BATCHEDREAD_TABLE,
INDEX_SJ and we may see others in the future. Although I could easily
disagree with their existence, I understand they are important. They allow
us to introduce new features while give control to the users to not use them
in case they found problems. Ideally, new features would not have bugs and
we would never need these kind of parameters, but we live in real world and
not on a perfect one
This parameter specifically change the behavior of the optimizer. And this
can be considered a high risk activity...
So, my advice: Turn it on on less critical systems and wait... If you don't
have problems, turn it on production.
I don't recall exactly if it was introduced in 11.10 or 11.50, but in any
case the bugs should be gone in latests fixpacks (don't recall seeing any
fix regarding this recently).
Regards.
Quote:
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Fernando Nunes
Portugal
http://informix-technology.blogspot.com
My email works... but I don't check it frequently...