Parameter Recommendations for Oracle Database 12c – Part I

Best Practice Hint

See also:

Parameter Recommendations for Oracle Database 12c – Part II


A few weeks ago we’ve published some parameter recommendations including several underscores but based on an internal discussion (still ongoing) we decided to remove this entry and split up the tasks. The optimizer team will take over parts of it and I’ll post an update as soon as something is published.

Preface

Please be advised – the following parameter list is mostly based on personal experience only. Some of them are officially recommended by Oracle Support. Always use proper testing mechanisms.

We strongly recommend SQL Performance Analyzer to verify the effect of any of those parameters.

How to read this blog post?

Never ever blindly set any underscore or hidden parameters because “somebody said” or “somebody wrote on a blog” (including this blog!) or “because our country has the best tuning experts worldwide” … Only trust Oracle Support if it’s written into a MOS Note or an official Oracle White Paper or if you work with a particular support or consulting engineer for quite a long time who understands your environment.

Important Parameter Settings

  • memory_target
    • Unexpected failing database upgrades with settings of  memory_target < 1GB where equal settings ofsga_target and pga_aggregate_target didn’t cause issues
    • It prevents the important use of HugePages
    • Avoid memory_target by any chance
    • Better use sga_target and pga_aggregate_target instead
  • pga_aggregate_limit
    • Be aware that it’s not a true limit.
      Monitor your PGA growth – you can’t rely exactly on pga_aggregate_limit
      .

Essential MOS Notes for Oracle Database 12.1.0.2

–Mike
.

5 thoughts on “Parameter Recommendations for Oracle Database 12c – Part I

  1. Kais,

    you won’t be surprised by my answer I’d guess 😉
    Please see the Preface above:

    Preface

    Please be advised – the following parameter list is mostly based on personal experience only. Some of them are officially recommended by Oracle Support. Always use proper testing mechanisms.

    We strongly recommend SQL Performance Analyzer to verify the effect of any of those parameters.

    Cheers
    Mike

  2. Sure – please browse through the blog as Roy and I gave a lot of recommendations within the past 12 months.

    In addition this one is the most important one meaning you’ll have to apply two fixes on top:
    https://blogs.oracle.com/UPGRADE/entry/enabling_adaptive_features_of_oracle

    Apart from that we can’t give "blindly" recommendations without knowing anything about your environment. A good rule is to have not too many parameter set. The more simple the better.

    Cheers
    Mike

  3. Pingback: Parameter Recommendations for Oracle Database 12c – Part II | Upgrade your Database - NOW!

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