What is an old buffer aging bug?
When I running onstat -P, I get

Percentages:
Data 12.30
Btree 86.78
Other 0.93


What do I should to do?

I am running Informix Dynamic Server 2000 Version 9.21.UC1 on Solaris 2.7.

I have performance problems.

In ONCONFIG I defined:

NETTYPE tlitcp,,,
DEADLOCK_TIMEOUT 60
RESIDENT 1
MULTIPROCESSOR 1
NUMCPUVPS 1
SINGLE_CPU_VP 1
NOAGE 1
AFF_SPROC 1
AFF_NPROCS 1

LOCKS 200000
BUFFERS 250000
NUMAIOVPS 2
PHYSBUFF 64
LOGBUFF 4
LOGSMAX 50
CLEANERS 1
SHMBASE 0xa000000
SHMVIRTSIZE 8000
SHMADD 8192
SHMTOTAL 0
CKPTINTVL 300
LRUS 8
LRU_MAX_DIRTY 60
LRU_MIN_DIRTY 50
LTXHWM 50
LTXEHWM 60
TXTIMEOUT 0x12c
STACKSIZE 32


Thanks.

----- Original Message -----
From: "Art S. Kagel" <kagel@bloomberg.net>
Newsgroups: comp.databases.informix
Sent: Monday, October 27, 2003 16:11
Subject: Re: how to use onstat -P


> On Sun, 26 Oct 2003 21:32:56 -0500, dusong wrote:
>
> There are three areas of interest on an onstat -P report.
>
> 1) The first line: Looking at the partnum zero (0) line, the page count in the
> 'other' column is an indication of the number of buffer cache pages that are
> currently unused since besides unused pages the number of pages that actually
> fall under the 'other' heading is tiny.
>
> A persistent high number here can indicate that you may be able to reduce the
> number of BUFFERS without affecting performance. However, be sure to check
> during peak loads to be certain.
>
> 2) The summary at the bottom. In a healthy OLTP/DSS environment there is
> normally a ratio of about 60-80% data pages, 15-35% index (BTree) pages and a
> small 'other' (excluding any excess 'other' noted above). Btree is normally
> about 1/3 of the Data value. Obviously in a DW environment with far fewer
> indexes this ratio will not hold. Note that if you are running an early 7.3 or
> 9.2 release and the Btree value is over 60% you may be running into an old
> buffer aging bug.
>
> 3) Each partnum line. You can use this information to determine what tables and
> or indexes are being heavily hit and may benefit from fragmentation over several
> dbspaces to spread the load and take advantage of parallel scans. Also for
> smaller tables - noticing a lookup table whose page count flutuates from most
> of the table's pages to very few many times a day may identify a candidate
> table to be marked RESIDENT.
>
> Art S. Kagel
>
>
>
>
>
> > How to use onstat -P(not -p) to tell informix server's performance question:?
> >
> >
> > --
> > Posted via http://dbforums.com

Hi,

The output of onstat -P is not bad.
I think you test changed :
MULTIPROCESSOR 0
NOAGE 0
AFF_SPROC 0
AFF_NPROCS 0

I need know about you environment for example layout of disk, physical memory, checkpoint time.

Can you send me this infromation ?

Gustavo.