v.18.12New Feature

Added system.query_thread_log Table and log_query_threads Setting

Official CH changelog text
Added the system.query_thread_log table, which contains information about each query execution thread. Added the log_query_threads setting. #2482
Added the system.query_thread_log table to provide detailed information about each query execution thread and introduced the log_query_threads setting to enable logging of these threads.

Why it matters

This feature helps users monitor and analyze the behavior of individual threads involved in query execution, allowing for better performance diagnostics and debugging at a more granular level.

How to use it

Enable the feature by setting the log_query_threads setting to 1 (true). After that, query information about execution threads can be retrieved from the system.query_thread_log table using standard SQL queries.

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