Exploring Modified Database Parameters v$parameter in Oracle

Show non-default parameters in the table v$parameter

Show non-default parameters in the table v$parameter

SQL Code

 1set pages 999 lines 100
 2col name format a30
 3col value format a50
 4select  name
 5,       value
 6from    v$parameter
 7where   isdefault = 'FALSE'
 8and     value is not null
 9order   by name
10/

Sample Oracle Output:

1no rows selected
2SQL>

Purpose:

  • To identify and display all non-default Oracle database initialization parameters that have been explicitly set to non-null values, providing insights into the database's current configuration and potential customizations that have been made. This aids in understanding database behavior, troubleshooting issues, and optimizing performance.

Breakdown:

Formatting Output:

  • set pages 999 lines 100: Adjusts display settings to accommodate potentially lengthy results.
  • col name format a30, col value format a50: Formats columns for readability and potentially long parameter names or values.

Querying Parameter Data:

  • select name, value from v$parameter: Retrieves information from the v$parameter view, which stores details about database initialization parameters.

  • Selects two columns:

    • name: Name of the parameter.
    • value: Current value of the parameter.

Filtering Parameters:

  • where isdefault = 'FALSE': Filters results to include only parameters that have been explicitly set to non-default values, excluding those using their default settings.
  • and value is not null: Further filters to exclude parameters with null values, focusing on those with explicitly set values.

Ordering Results:

  • order by name: Presents results in alphabetical order by parameter name for easy navigation and lookup.

Key Points:

  • Non-default Focus: Identifies parameters that have been intentionally modified from their defaults, highlighting potential customizations or optimizations made for the specific database environment.
  • Explicit Values: Shows only parameters with non-null values, indicating active configuration settings.
  • Essential Information: Parameter names and values provide crucial insights into database behavior and configuration choices.
  • Dynamic View: Thev$parameterview reflects the current state of parameters in the running instance.

Insights and Explanations:

  • Configuration Understanding:

    • Reveals how the database has been customized, aiding in understanding its behavior and potential performance implications.
  • Troubleshooting:

    • Comparing non-default parameter values with known best practices or troubleshooting guides can help identify potential configuration issues or conflicts.
  • Performance Tuning:

    • Understanding parameter settings is essential for performance tuning, as adjusting certain parameters can significantly impact database behavior.
  • Security Auditing:

    • Reviewing non-default parameters can reveal potential security vulnerabilities or misconfigurations that might need attention.
  • Customization:

    • Can be modified to filter for specific parameter names or values based on analysis needs.
  • Regular Monitoring:

    • Incorporating this query into regular database monitoring can help track configuration changes and identify potential issues proactively.

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