| trace | Array(UInt64) | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Stack trace at the moment of sampling. Each element is a virtual memory address inside ClickHouse server process. | |
| increment | Int64 | 0.00 B | 0.00 B | 15.09 thousand | 0 | | For trace type ProfileEvent is the amount of increment of profile event, for other trace types is 0. | |
| revision | UInt32 | 0.00 B | 0.00 B | 15.09 thousand | 0 | | ClickHouse server build revision. | |
| event_date | Date | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Date of sampling moment. | |
| size | Int64 | 0.00 B | 0.00 B | 15.09 thousand | 0 | | For trace types Memory, MemorySample or MemoryPeak is the amount of memory allocated, for other trace types is 0. | |
| ptr | UInt64 | 0.00 B | 0.00 B | 15.09 thousand | 0 | | The address of the allocated chunk. | |
| timestamp_ns | UInt64 | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Timestamp of the sampling moment in nanoseconds. | |
| trace_type | Enum8('Real' = 0, 'CPU' = 1, 'Memory' = 2, 'MemorySample' = 3, 'MemoryPeak' = 4, 'ProfileEvent' = 5) | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Trace type: `Real` represents collecting stack traces by wall-clock time. `CPU` represents collecting stack traces by CPU time. `Memory` represents collecting allocations and deallocations when memory allocation exceeds the subsequent watermark. `MemorySample` represents collecting random allocations and deallocations. `MemoryPeak` represents collecting updates of peak memory usage. `ProfileEvent` represents collecting of increments of profile events. | |
| event_time_microseconds | DateTime64(6) | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Timestamp of the sampling moment with microseconds precision. | |
| event | LowCardinality(String) | 0.00 B | 0.00 B | 15.09 thousand | 0 | | For trace type ProfileEvent is the name of updated profile event, for other trace types is an empty string. | |
| hostname | LowCardinality(String) | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Hostname of the server executing the query. | |
| thread_id | UInt64 | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Thread identifier. | |
| event_time | DateTime | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Timestamp of the sampling moment. | |
| query_id | String | 0.00 B | 0.00 B | 15.09 thousand | 0 | | Query identifier that can be used to get details about a query that was running from the query_log system table. |
