OPTIMIZER-Problem

From: Ralf Korell <ralf_at_hydrogen.emi.de>
Date: 1995/08/10
Message-ID: <40d44j$377_at_unlisys.unlisys.net>#1/1

Hi, DB-Gurus !

I have three major problems, which are not easy to unsterstand, therefore I have decided to post every problem in a single mail.

Q 1: OPTIMIZER-Problem
Q 2: Performance-Problem (Hardware ?) 
Q 3: failsave database ? 


________________________________________________________________

General Information : we use oracle V 7.1.4.1.0, for performance testing I involved SQL*Plus: Release 3.1.3.2.1 OS is HP-UX V. 9.05

---

so far, let's start with Q 2:
Performance-Problem (Hardware ?)

We got a performance lack on our customer's machine (HP 9000/887, HP-UX 9.05):

I've simulated a multi-user connect whith a simple Pro*C-program, which performs the same select-statment 10.000 times. On our developer machine (HP 9000/715, HP-UX 9.05) there is no difference in answering-time for, let's say 20 parallel connects. Somewhat strange happens on the HP 800 : the more connects, the higher the answering time ! (e.g. from 1.1 sec. for 1 connect to +30 seconds for 20 connects).

Network problems cannot be the reason (fast FDDI Backbone !), the problem is the same, when I run the program on the server.

the tkprof-utility gives the following
timed statistic for 7 calls of the select statement : on 715 (which runs fast) :

call count cpu elapsed disk query current rows -------- ------- -------- --------- -------- -------- ------- ----------

Parse           7      0.08       0.08        0        0       0           0
Execute         7      0.03       0.03        0        0       0           0
Fetch           7      0.09       0.15       27    81345       0           0

on 800, which slows down :  

call count cpu elapsed disk query current rows -------- ------- -------- --------- -------- -------- ------- ----------

Parse           6      0.01       0.01        0        0       0           0
Execute         6      0.00       0.00        0        0       0           0
Fetch           6      4.54      12.46        0    82680       0           0


Qs : Has anybody experiences with oracle on a HP 800 ?
     Is this really a hardware-problem ?
     Is there a solution ?
     
    

Any comments, suggestions, or questions are appreciated !

Please e-mail me directly and I will post a digest in the newsgroup.

-- 
                              ,,,
                             (o o)
~*~~*~~*~~*~~*~~*~~*~~*~~oOO~~(_)~~OOo~*~~*~~*~~*~~*~~*~~*~~*~~*~~*~
       Please apologize but english is not my native language

           R. Korell, EMi GmbH (Medical Informatics)
         Karl-Marx-Str. 204 , D 12055 Berlin, Germany
 Internet: korell_at_emi.de     Compuserve: 100601.3532_at_compuserve.com
    phone:    +49 (30) 6814032  fax:        +49 (30) 6814031
~*~~*~~*~~*~~*~~*~~*~~*~~(___)~*~(___)~*~~*~~*~~*~~*~~*~~*~~*~~*~~*~
The opinions you read here are mine and not necessarily those of my
employers. Although, I must say they are the truth, the whole truth,
and nothing like the truth. As far as I'm concerned anyway...

Received on Thu Aug 10 1995 - 00:00:00 CEST