Topic Suggestions

February 23rd, 2009
Goto comments Leave a comment

This page is a placeholder for the readers of this blog to suggest topics of future blog posts. I can’t guarantee I will be able to write an entire blog post about your topic suggestion, but I can guarantee that I will read it.

Leave your topic suggestion in a comment and stay tuned…

Post to Twitter Tweet This Post

  1. Trackbacks

  2. No trackbacks yet.

  1. Comments

  2. Steven Andrew
    April 9th, 2009 at 22:54 | #1
    Reply | Quote

    Hi Greg,

    The topic i wanted to discuss has been prevalent in almost all the corporations i have worked so far. And i would like to hear your perspective of addressing it.

    Generally engineers deliver software builds to QA and they do functional testing and then perform load/stress testing. Problems that are caught mostly in production like oracle choosing bad index vs. good index for the query are not generally caught in QA’s performance cycles. I know oracle has made good attempt to fix this in 11g using adaptive cursor sharing but in 10gR2 (.4), how do we avoid these scenario’s where oracle doesn’t automatically recover from using bad plan to good plan. I have seen most cases were load test environment will not have representative dataset to begin with there by everything working hunky dory on performance labs but discover later to see problems in production.

    What is the best way to simulate production dataset to avoid surprises going into production. I believe if load performance test is done on representative dataset, then oracle would generate appropriate stats thereby choosing optimum or sub-optimal execution plans which greatly helps to figure out the problem before going into production environments.

    Even if this topic don’t qualify for blog spot, if you could give your ideas of how one should address these issues would be appreciated.

    Thanks
    Steve

  3. Prasanna Rajagopal
    August 30th, 2009 at 06:57 | #2
    Reply | Quote

    @Steven Andrew
    Hello Steve
    Oracle 11g Enterprise Edition has an option called Real Application Testing (RAT) that would help you capture production workload and replay it in test environment. It is composed of two components Database Replay and SQL Performance Analyzer. You can learn more about RAT at:
    http://www.oracle.com/database/real-application-testing.html
    and
    here:
    http://download.oracle.com/docs/cd/B28359_01/server.111/e12253/toc.htm
    There are many requirements to using RAT, you can learn about all those on the above two sites. I hope this is useful.
    Thanks
    -Prasanna

  4. Krish
    February 1st, 2010 at 19:55 | #3
    Reply | Quote

    Hi Greg,

    Good blog and i have learned quite a few things over here. I have couple of questions. Is Exadata just Oracle RAC ? I think its not. Is it a shared nothing architecture ? Please guide me to some documentation.

    Thanks
    Krish

  5. Greg Rahn
    February 1st, 2010 at 21:56 | #4
    Reply | Quote

    @Krish

    Thanks for the comment and glad you have found the blog a good learning tool. That’s my intent ;)

    Exadata is modular, scalable, intelligent storage for Oracle databases. I guess one could call it shared nothing but it is no more (or no less) shared nothing than any modular scalable non-Exadata storage. Exadata storage does not require Oracle RAC, it just happens to be paired with RAC in the Oracle Database Machine, but it can be used with any Linux host (RAC or not).

    Point your browser to http://oracle.com/exadata and expand the right hand columns (Technical Information, Data Sheets & FAQ, etc.) for numerous papers.

  6. Krish
    February 1st, 2010 at 23:21 | #5
    Reply | Quote

    Thanks Greg. Appreciate your prompt response.