v.18.12New Feature

New Logging for Query Settings in system.query_log and system.processes Tables

Official CH changelog text
The system.query_log and system.processes (SHOW PROCESSLIST) tables now have information about all changed settings when you run a query (the nested structure of the Settings data). Added the log_query_settings setting. #2482
The system.query_log and system.processes (SHOW PROCESSLIST) tables have been enhanced to include detailed information about all changed query settings in a nested Settings structure. A new setting, log_query_settings, has been introduced to control this behavior.

Why it matters

This feature enables users to track and analyze all modifications to query settings during execution, improving diagnostics and debugging capabilities by providing comprehensive visibility into the exact settings applied for each query.

How to use it

To enable logging of changed query settings, set the log_query_settings setting to 1. Once enabled, the system.query_log and system.processes tables will include a nested Settings structure detailing all modified settings for each query.

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