Re: Oracle Performance

From: Juan Cachito Reyes Pacheco <jreyes_at_dazasoftware.com>
Date: Thu, 11 Mar 2004 11:43:03 -0400
Message-ID: <017301c4077f$90f17200$2501a8c0@dazasoftware.com>

RE: Oracle PerformanceHonestly I don't agree with this, I don't think there is any need to use rule, in Oracle 9i, CBO works perfectly with this kind of situation, the problem must be find and fixed.

Original Message ----- From: Whittle Jerome Contr NCI To: oracle-l_at_freelists.org Cc: VChoque Sent: Thursday, March 11, 2004 10:46 AM Subject: RE: Oracle Performance

You have 5 indexes of which 3 have the fields in your SQL. You may be better off with one index on the COD_IMPORTACION, COD_NIVEL_CALIDAD, and NRO_FACTURACION fields. After creating the index, analyze the table before running your sql.

You might also just want to try to use the Rule hint. It's usually one of the first things I try with slow SQL. If it runs much faster with the Rule hint, something is going on to confuse the CBO.

  SELECT /*+ RULE */ COUNT(NRO_FACTURACION) ....   Jerry Whittle
  ASIFICS DBA
  NCI Information Systems Inc.
  jerome.whittle_at_scott.af.mil
  618-622-4145

-----Original Message-----

From: Huascar Espinoza [SMTP:hespinoza_at_superele.gov.bo]

To realize the test, we have the basic following structure (similar on Oracle 9i and SQL Server 7.0):

      
    ·        Table "SC_FACTURACION" have the following indexes: 

        a.. COD_IMPORTACION 
        b.. NRO_FACTURACION 
        c.. COD_FACTURA_ESTIMADA 
        d.. COD_FACTURA_REFACTURADA 
        e.. COD_MOTIVO_ESTIMACION 
        f.. COD_NIVEL_CALIDAD. 
    ·        Table "GE_HISTORICO_IMPORTACION" has 30 registers. 
    ·        Table "SC_FACTURACION" has 1,885,618 registers. 
      
    On 'SC_FACTURACION' we execute the following SQL sentences: 
      

      1.. SELECT COUNT(NRO_FACTURACION) FROM SC_FACTURACION WHERE COD_IMPORTACION = '14' AND COD_NIVEL_CALIDAD = '1' 
      2.. SELECT MAX(NRO_FACTURACION) FROM SC_FACTURACION WHERE COD_IMPORTACION = '14' AND COD_NIVEL_CALIDAD = '1' 
      3.. SELECT MIN(NRO_FACTURACION) FROM SC_FACTURACION WHERE COD_IMPORTACION = '14' AND COD_NIVEL_CALIDAD = '1' 
     
    The results are:

    Sentence
    Performance ORACLE 9i
    Performance MS SQL Server 7.0
    1
    2 minutes
    20 secs.
    2
    2 minutes
    1 sec.
    3
    50 secs.
    1 secs.

The servers are the followins features:

    ORACLE 9i Server
    Processor
    Intel Pentium IV - 2.4 GHz
    RAM Memory
    512 MB

    S SQL Server 7.0 Server
    Processor
    Intel Celeron 2.4 GHz
    RAM Memory
    380 MB

      
      
    Please let me know, why the performance of Oracle is so low. 
      
    Thank you! 
      
    Huáscar Espinoza

-----Mensaje original-----

De: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org] En nombre de DENNIS WILLIAMS

Huascar

Normal? No. In order to help diagnose your situation, please post more details. Like your query, the sizes of your tables, etc. Have you analyzed the tables in Oracle?

    Dennis Williams
    DBA
    Lifetouch, Inc.
    dwilliams_at_lifetouch.com

-----Original Message-----

From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]On

¿Is it normal that a SQL sentence: MAX or MIN, execute over 1.5 minutes on Oracle 9i, and in 1 sec. on SQL Server 7.0 (2 millions of registers), using equals data structures and servers? ¿Why occur this situation?

Thank you,

Huascar Espinoza

Please see the official ORACLE-L FAQ: http://www.orafaq.com

To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line.

--
Archives are at http://www.freelists.org/archives/oracle-l/
FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html
-----------------------------------------------------------------

Received on Thu Mar 11 2004 - 13:43:40 CST