Skip to main content
Skip to main content
Edit this page

stack_trace

Querying in ClickHouse Cloud

The data in this system table is held locally on each node in ClickHouse Cloud. Obtaining a complete view of all data, therefore, requires the clusterAllReplicas function. See here for further details.

Contains stack traces of all server threads. Allows developers to introspect the server state.

To analyze stack frames, use the addressToLine, addressToLineWithInlines, addressToSymbol and demangle introspection functions.

Columns:

  • thread_name (String) — Thread name.
  • thread_id (UInt64) — Thread identifier.
  • query_id (String) — Query identifier that can be used to get details about a query that was running from the query_log system table.
  • trace (Array(UInt64)) — A stack trace which represents a list of physical addresses where the called methods are stored.
Tip

Check out the Knowledge Base for some handy queries, including how to see what threads are currently running and useful queries for troubleshooting.

Example

Enabling introspection functions:

Getting symbols from ClickHouse object files:

Getting filenames and line numbers in ClickHouse source code:

See Also

  • Introspection Functions — Which introspection functions are available and how to use them.
  • system.trace_log — Contains stack traces collected by the sampling query profiler.
  • arrayMap — Description and usage example of the arrayMap function.
  • arrayFilter — Description and usage example of the arrayFilter function.