PostgreSQL Error Handling Settings via pg_settings

PostgreSQL Error Handling Settings Query Guide using pg_settings

PostgreSQL's pg_settings system view provides comprehensive information about database configuration parameters, particularly those related to error handling and logging. This query helps database administrators monitor and analyze error-related settings effectively.

Query Breakdown

Original Query:

 1SELECT
 2    name,
 3    setting,
 4    -- category,
 5    vartype,
 6    short_desc,
 7    -- enumvals,
 8    source,
 9    min_val,
10    max_val,
11    boot_val,
12    reset_val,
13    -- not available on PostgreSQL < 9.5
14    pending_restart
15FROM
16    pg_settings
17WHERE
18    -- Error Handling
19    category ILIKE '%Error%';

Purpose and Functionality

This PostgreSQL query retrieves configuration parameters specifically related to error handling from the pg_settings system catalog. It helps database administrators understand current error management settings, their values, and operational status.

Column Explanations

Core Information Columns

• name: The configuration parameter name
• setting: Current value of the parameter
• vartype: Data type of the parameter (bool, enum, integer, real, string)
• short_desc: Brief description of what the parameter controls

Value Range and Source Information

• source: How the parameter was set (default, configuration file, command line, etc.)
• min_val: Minimum allowed value for numeric parameters
• max_val: Maximum allowed value for numeric parameters
• boot_val: Default value at server startup
• reset_val: Value that would be used if the parameter is reset

Operational Status

• pending_restart: Indicates if a server restart is required for changes to take effect (PostgreSQL 9.5+)

Key Insights

Error Category Parameters

The query filters for parameters containing "Error" in their category, typically including:

• log_error_verbosity: Controls the amount of detail in error messages
• exit_on_error: Determines if the session should terminate on errors
• log_min_error_statement: Sets the minimum severity level for logging SQL statements that cause errors

Configuration Management Benefits

This query provides administrators with essential information for:

• Monitoring current error handling behavior
• Planning configuration changes
• Understanding parameter dependencies
• Troubleshooting logging issues

Practical Applications

Database Monitoring

Database administrators can use this query to verify error handling configurations across different PostgreSQL instances, ensuring consistent behavior in production environments.

Troubleshooting Support

When investigating database issues, this query helps identify relevant error handling settings that might affect problem diagnosis and resolution.

Configuration Auditing

Regular execution of this query supports configuration management practices by documenting current settings and tracking changes over time.

Version Compatibility Notes

The pending_restart column is only available in PostgreSQL 9.5 and later versions. For earlier versions, this column should be removed from the SELECT list or commented out to avoid query errors.

Best Practices

Regular Monitoring

Execute this query periodically to ensure error handling settings remain appropriate for your environment and workload requirements.

Documentation Integration

Include query results in your database documentation to maintain accurate configuration records and support change management processes.

Performance Considerations

The pg_settings view reads directly from server memory, making this query lightweight and suitable for frequent execution without performance impact.

References

• PostgreSQL Official Documentation - System Views - Complete reference for pg_settings system view and all available columns
• PostgreSQL Error Reporting and Logging - Detailed guide on error handling configuration parameters
• PostgreSQL System Administration - Comprehensive database administration documentation including configuration management