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# system.opentelemetry_span_log {#system_tables-opentelemetry_span_log}
Contains information about [trace spans ](https://opentracing.io/docs/overview/spans/ ) for executed queries.
Columns:
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- `trace_id` ([UUID](../../sql-reference/data-types/uuid.md)) — ID of the trace for executed query.
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- `span_id` ([UInt64](../../sql-reference/data-types/int-uint.md)) — ID of the `trace span` .
- `parent_span_id` ([UInt64](../../sql-reference/data-types/int-uint.md)) — ID of the parent `trace span` .
- `operation_name` ([String](../../sql-reference/data-types/string.md)) — The name of the operation.
- `start_time_us` ([UInt64](../../sql-reference/data-types/int-uint.md)) — The start time of the `trace span` (in microseconds).
- `finish_time_us` ([UInt64](../../sql-reference/data-types/int-uint.md)) — The finish time of the `trace span` (in microseconds).
- `finish_date` ([Date](../../sql-reference/data-types/date.md)) — The finish date of the `trace span` .
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- `attribute.names` ([Array](../../sql-reference/data-types/array.md)([String](../../sql-reference/data-types/string.md))) — [Attribute ](https://opentelemetry.io/docs/go/instrumentation/#attributes ) names depending on the `trace span` . They are filled in according to the recommendations in the [OpenTelemetry ](https://opentelemetry.io/ ) standard.
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- `attribute.values` ([Array](../../sql-reference/data-types/array.md)([String](../../sql-reference/data-types/string.md))) — Attribute values depending on the `trace span` . They are filled in according to the recommendations in the `OpenTelemetry` standard.
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**Example**
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Query:
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``` sql
SELECT * FROM system.opentelemetry_span_log LIMIT 1 FORMAT Vertical;
```
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Result:
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``` text
Row 1:
──────
trace_id: cdab0847-0d62-61d5-4d38-dd65b19a1914
span_id: 701487461015578150
parent_span_id: 2991972114672045096
operation_name: DB::Block DB::InterpreterSelectQuery::getSampleBlockImpl()
start_time_us: 1612374594529090
finish_time_us: 1612374594529108
finish_date: 2021-02-03
attribute.names: []
attribute.values: []
```
**See Also**
- [OpenTelemetry ](../../operations/opentelemetry.md )
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[Original article ](https://clickhouse.com/docs/en/operations/system_tables/opentelemetry_span_log ) <!--hide-->