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:

1
2no rows selected
3SQL>

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: The v$parameter view 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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