Wednesday, July 23, 2008

Tuning Database Links

  • Drill-Down Monitoring of Database Servers

  • The article presents a process for identifying and resolving problems with the performance of database servers. Learn how to monitor and tune databases, as well as how to recognize if a shared memory segment uses ISM (Intimate Shared Memory).

  • Oracle Database Tuning

  • For optimum performance an Oracle database should be regularly tuned. Only tune a database after it has been up and running for a little while.

    • Tuning the cache hit ratio

    • Tuning the library cache

    • Tuning the log buffer

    • Tuning buffer cache hit ratio

    • Tuning sorts

    • Tuning rollback segments

    • Identifying missing indexes

    • Identifying index fragmentation

    • Identifying free list contention

    • Identify significant reparsing of SQL

    • Reducing database fragmentation

    • Rebuilding indexes

    • Reduce thrashing or poor system performance (or how to un-tune oracle?!)


  • Database Performance Tuning

    • What database aspects should be monitored?

    • Why and when should one tune?

    • Where should the tuning effort be directed?

    • What tools/utilities does Oracle provide to assist with performance tuning?

    • What is STATSPACK and how does one use it?

    • When is cost based optimization triggered?

    • How can one optimize %XYZ% queries?

    • Where can one find I/O statistics per table?

    • My query was fine last week and now it is slow. Why?

    • Is my index being used or nor?

    • Why is Oracle not using the damn index?

    • When should one rebuild an index?

    • How does one tune Oracle Wait events?

    • What is the difference between DBFile Sequential and Scattered Reads?

    • Where can one get more info about Oracle Tuning?

    • How does one tune the Redo Log Buffer?


  • Tuning Oracle on Windows for Maximum Performance on PowerEdge Servers

  • Executive Summary Microsoft
    Windows is an excellent platform for running the Oracle
    Database server. The Windows platform provides an easy to use graphical environment for managing your Oracle Database server. In addition, the Windows platform provides support for not only the Oracle Database server, but other Oracle add-ons and products as well, such as:

    • Oracle Real Application Clusters (RAC)

    • Oracle Fail Safe (using Microsoft Cluster Services)

    • Oracle Application Server (AS)

    • Oracle E-Business Suite

    • Both 32-bit and 64-bit versions

    In general the Windows platform is tuned in much the same manner as any other Oracle Database server; however, there are some key differences. These differences are mainly in the use of memory (32-bit Oracle on Windows) and in the process model. Since Oracle on Windows uses a threaded model, there are some additional concerns that you will not have on most UNIX platforms. As long as you are aware of these issues and have tuned appropriately, the Windows platform is a high-performing and stable platformfor your Oracle Database server. This paper covers some of the general Oracle tuning practices as well as specific tuning for the Windows platform.

    Link: Oracle on Windows Tuning