system.error_log

System table containing the history of error values from table system.errors, periodically flushed to disk.

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.

Description

Contains history of error values from table system.errors, periodically flushed to disk.

It is safe to truncate or drop this table at any time.

Columns

• hostname (LowCardinality(String)) — Hostname of the server executing the query.
• clickhouse_version (LowCardinality(String)) — Version of the ClickHouse server that produced the row.
• system_processor (LowCardinality(String)) — CPU architecture of the ClickHouse server that produced the row.
• event_date (Date) — Event date.
• event_time (DateTime) — Event time.
• code (Int32) — Error code.
• error (LowCardinality(String)) — Error name.
• value (UInt64) — Number of errors happened in time interval.
• remote (UInt8) — Remote exception (i.e. received during one of the distributed queries).
• last_error_time (DateTime) — The time when the last error happened.
• last_error_message (String) — Message for the last error.
• last_error_query_id (String) — Id of a query that caused the last error (if available).
• last_error_trace (Array(UInt64)) — A stack trace of the last error. On ELF platforms except FreeBSD, addresses inside the main ClickHouse binary are stored as physical file offsets, and other addresses are virtual memory addresses inside the ClickHouse server process.
• last_error_symbols (Array(LowCardinality(String))) — Demangled symbol names corresponding to last_error_trace.
• last_error_lines (Array(LowCardinality(String))) — File names with line numbers corresponding to last_error_trace.

last_error_symbols and last_error_lines are resolved from the binary’s symbol table and debug info. last_error_symbols is populated wherever the symbol table is available (Linux and macOS builds). last_error_lines additionally requires DWARF debug info - read directly from the binary on Linux, or from a co-located .dSYM bundle on macOS - so it is empty when that debug info is not available. Both arrays are empty on platforms without introspection support (for example FreeBSD).

Example

SELECT * FROM system.error_log LIMIT 1 FORMAT Vertical;

Row 1:
──────
hostname:            clickhouse.testing.internal
event_date:          2025-11-11
event_time:          2025-11-11 11:35:28
code:                60
error:               UNKNOWN_TABLE
value:               1
remote:              0
last_error_time:     2025-11-11 11:35:28
last_error_message:  Unknown table expression identifier 'system.table_not_exist' in scope SELECT * FROM system.table_not_exist
last_error_query_id: 77ad9ece-3db7-4236-9b5a-f789bce4aa2e
last_error_trace:    [100506790044914,100506534488542,100506409937998,100506409936517,100506425182891,100506618154123,100506617994473,100506617990486,100506617988112,100506618341386,100506630272160,100506630266232,100506630276900,100506629795243,100506633519500,100506633495783,100506692143858,100506692248921,100506790779783,100506790781278,100506790390399,100506790380047,123814948752036,123814949330028]

See Also

• error_log setting — Enabling and disabling the setting.
• system.errors — Contains error codes with the number of times they have been triggered.
• Monitoring — Base concepts of ClickHouse monitoring.