> ## Documentation Index
> Fetch the complete documentation index at: https://private-7c7dfe99-parallel-read-in-order-multi-part.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

> System table containing information about stack traces for fatal errors.

# system.crash_log

<Info>
  **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](/reference/system-tables/overview#system-tables-in-clickhouse-cloud) for further details.
</Info>

<h2 id="description">
  Description
</h2>

Contains information about stack traces for fatal errors. The table does not exist in the database by default, it is created only when fatal errors occur.

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

<h2 id="columns">
  Columns
</h2>

* `hostname` ([LowCardinality(String)](/reference/data-types/lowcardinality)) — The hostname where the crash occurred.
* `clickhouse_version` ([LowCardinality(String)](/reference/data-types/lowcardinality)) — Version of the ClickHouse server that produced the row.
* `system_processor` ([LowCardinality(String)](/reference/data-types/lowcardinality)) — CPU architecture of the ClickHouse server that produced the row.
* `event_date` ([Date](/reference/data-types/date)) — The date of the crash.
* `event_time` ([DateTime](/reference/data-types/datetime)) — The time of the crash.
* `timestamp_ns` ([UInt64](/reference/data-types/int-uint)) — Timestamp of the event with nanoseconds.
* `signal` ([Int32](/reference/data-types/int-uint)) — Signal number.
* `signal_code` ([Int32](/reference/data-types/int-uint)) — Signal code. Provides additional context about the signal cause.
* `thread_id` ([UInt64](/reference/data-types/int-uint)) — Thread ID.
* `query_id` ([String](/reference/data-types/string)) — Query ID.
* `query` ([String](/reference/data-types/string)) — Query text that was being executed when the crash occurred.
* `trace` ([Array(UInt64)](/reference/data-types/array)) — Stack trace at the moment of crash. 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.
* `trace_full` ([Array(String)](/reference/data-types/array)) — Stack trace at the moment of crash. Each element contains a called method inside ClickHouse server process.
* `fault_address` ([Nullable(UInt64)](/reference/data-types/nullable)) — Memory address that caused the fault.
* `fault_access_type` ([String](/reference/data-types/string)) — Type of memory access that caused the fault (e.g., 'read', 'write').
* `signal_description` ([String](/reference/data-types/string)) — Human-readable description based on signal\_code (e.g., 'Address not mapped to object').
* `current_exception_trace_full` ([Array(String)](/reference/data-types/array)) — Current exception stack trace with symbolized frames (std::terminate crashes only).
* `version` ([String](/reference/data-types/string)) — ClickHouse server version.
* `revision` ([UInt32](/reference/data-types/int-uint)) — ClickHouse server revision.
* `build_id` ([String](/reference/data-types/string)) — BuildID that is generated by compiler.
* `git_hash` ([String](/reference/data-types/string)) — Git commit hash of the ClickHouse source code.
* `architecture` ([String](/reference/data-types/string)) — CPU architecture (e.g., x86\_64, aarch64).

<h2 id="example">
  Example
</h2>

```sql title="Query" theme={null}
SELECT * FROM system.crash_log ORDER BY event_time DESC LIMIT 1;
```

```text title="Response" theme={null}
Row 1:
──────
hostname:     clickhouse.eu-central1.internal
event_date:   2020-10-14
event_time:   2020-10-14 15:47:40
timestamp_ns: 1602679660271312710
signal:       11
thread_id:    23624
query_id:     428aab7c-8f5c-44e9-9607-d16b44467e69
trace:        [188531193,...]
trace_full:   ['3. DB::(anonymous namespace)::FunctionFormatReadableTimeDelta::executeImpl(std::__1::vector<DB::ColumnWithTypeAndName, std::__1::allocator<DB::ColumnWithTypeAndName> >&, std::__1::vector<unsigned long, std::__1::allocator<unsigned long> > const&, unsigned long, unsigned long) const @ 0xb3cc1f9 in /home/username/work/ClickHouse/build/programs/clickhouse',...]
version:      ClickHouse 20.11.1.1
revision:     54442
build_id:
```

<h2 id="see-also">
  See also
</h2>

* [trace\_log](/reference/system-tables/trace_log) system table