Re: partition buffer summary - Btree percentage
Posted in 1999
Topics: Installation, Setup & Upgrades
Hello,
I am very interested in the script of Mr. Miller for finding invalid
page types.
Is it still possible to get one copy of this script?
If yes, could you please send me a copy to MZernikow@heyde.de.
Many Thanks in advance
MfG
Mathias Zernikow
In article <7s7dav$t2j$1@nnrp1.deja.com>,
plsmith@my-deja.com wrote:
> Vardan
>
> You have almost certainly run into bug no. 115327 and you should be
> able to request a patch to fix it.
> It is a bug in 7.2x and 7.3x whereby btree pages can be generated with
> an invalid page type. This page type is then handled incorrectly by
the
> new 7.30 buffer priority management.
> Dropping and rebuilding affected indexes is a reasonable workaround,
but
> the problme could re-occur depending on the habits of you application.
> The invalid page types are generated when all the rows are deleted
from
> a table thus compressing the index down to a single page. When rows
are
> inserted an invalid page type is then copied through all the leaf
nodes.
> If you look at onstat -R you will see that the majority of pages are
in
> the medium-high category, whereas data pages are medium-low. Leaf node
> pages should also be medium low, but because of the invalid page type
> they are placed in the medium-high category, thus squeezing out the
data
> pages. If you install a patch you should see a reversal of these
> percentages and an increase in your read cache.
> If you talk to Informix tech support refer them to case No. 861366
which
> contains a reproducable example.
> I have a small script which will identify invalid pages types (sql
> courtesy of John Miller, thanks ).
>
> email me if you would like a copy.
>
> hth
> Pete Smith
> Logica
>
> In article <7s5n3g$mq7$1@nnrp1.deja.com>,
> Vardan Aroustamian <vaar@geocities.com> wrote:
> > Hello,
> >
> > I'm new to SAP environment and would like to get some input
> > from experienced users.
> >
> > Anyone knows of some "usual" percentage for Data vs. Btree
> > pages in the buffer pool (from onstat -P output).
> >
> > Currently I have
> >
> > Percentages:
> > Data 20.09
> > Btree 77.75
> > Other 2.16
> >
> > I heard about some bug when Btree is more than 90%.
> > I'm not sure will I reach that number.
> >
> > Informix 7.30.UC7XB
> > SunOS 5.5.1
> >
> > Database ~50GB
> > SAP 4.5
> >
> > Actually I believe this is not SAP specific question.
> > Anyway, thanks for any information.
> >
> > Vardan
> >
> > --
> > Vardan Aroustamian
> > vaar@geocities.com
> >
> > Sent via Deja.com http://www.deja.com/
> > Share what you know. Learn what you don't.
> >
>
> Sent via Deja.com http://www.deja.com/
> Share what you know. Learn what you don't.
>
Sent via Deja.com http://www.deja.com/
Before you buy.
Related threads
- Informix TEXT DATATYPE and Powerbuilder BLOB Data type compatibility
- Re: Assert Failed: Page Check Error in bfput
- How to check for all tools installed on a server