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.