ClickHouse/docs/en/operations/system-tables/asynchronous_insert_log.md

slug
/en/operations/system-tables/asynchronous_insert_log

asynchronous_insert_log

Contains information about async inserts. Each entry represents an insert query buffered into an async insert query.

To start logging configure parameters in the asynchronous_insert_log section.

The flushing period of data is set in flush_interval_milliseconds parameter of the asynchronous_insert_log server settings section. To force flushing, use the SYSTEM FLUSH LOGS query.

ClickHouse does not delete data from the table automatically. See Introduction for more details.

Columns:

• hostname (LowCardinality(String)) — Hostname of the server executing the query.
• event_date (Date) — The date when the async insert happened.
• event_time (DateTime) — The date and time when the async insert finished execution.
• event_time_microseconds (DateTime64) — The date and time when the async insert finished execution with microseconds precision.
• query (String) — Query string.
• database (String) — The name of the database the table is in.
• table (String) — Table name.
• format (String) — Format name.
• query_id (String) — ID of the initial query.
• bytes (UInt64) — Number of inserted bytes.
• exception (String) — Exception message.
• status (Enum8) — Status of the view. Values:
  • 'Ok' = 1 — Successful insert.
  • 'ParsingError' = 2 — Exception when parsing the data.
  • 'FlushError' = 3 — Exception when flushing the data.
• flush_time (DateTime) — The date and time when the flush happened.
• flush_time_microseconds (DateTime64) — The date and time when the flush happened with microseconds precision.
• flush_query_id (String) — ID of the flush query.

Example

Query:

SELECT * FROM system.asynchronous_insert_log LIMIT 1 \G;

Result:

hostname:                clickhouse.eu-central1.internal
event_date:              2023-06-08
event_time:              2023-06-08 10:08:53
event_time_microseconds: 2023-06-08 10:08:53.199516
query:                   INSERT INTO public.data_guess (user_id, datasource_id, timestamp, path, type, num, str) FORMAT CSV
database:                public
table:                   data_guess
format:                  CSV
query_id:                b46cd4c4-0269-4d0b-99f5-d27668c6102e
bytes:                   133223
exception:
status:                  Ok
flush_time:              2023-06-08 10:08:55
flush_time_microseconds: 2023-06-08 10:08:55.139676
flush_query_id:          cd2c1e43-83f5-49dc-92e4-2fbc7f8d3716

See Also

• system.query_log — Description of the query_log system table which contains common information about queries execution.
• system.asynchronous_inserts — This table contains information about pending asynchronous inserts in queue.