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system.filesystem_cache_log

Contains a history of all events occurred with filesystem cache for objects on a remote filesystem.

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

Columns:

  • hostname (LowCardinality(String)) — Hostname
  • event_date (Date) — Event date
  • event_time (DateTime) — Event time
  • query_id (String) — Id of the query
  • source_file_path (String) — File segment path on filesystem
  • file_segment_range (Tuple(UInt64, UInt64)) — File segment range
  • total_requested_range (Tuple(UInt64, UInt64)) — Full read range
  • key (String) — File segment key
  • offset (UInt64) — File segment offset
  • size (UInt64) — Read size
  • read_type (String) — Read type: READ_FROM_CACHE, READ_FROM_FS_AND_DOWNLOADED_TO_CACHE, READ_FROM_FS_BYPASSING_CACHE
  • read_from_cache_attempted (UInt8) — Whether reading from cache was attempted
  • read_buffer_id (String) — Internal implementation read buffer id
  • user_id (String) — User id of the user which created the file segment