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Contains information about merges and part mutations currently in process for tables in the MergeTree family.


  • database (String) — The name of the database the table is in.
  • table (String) — Table name.
  • elapsed (Float64) — The time elapsed (in seconds) since the merge started.
  • progress (Float64) — The percentage of completed work from 0 to 1.
  • num_parts (UInt64) — The number of pieces to be merged.
  • result_part_name (String) — The name of the part that will be formed as the result of merging.
  • is_mutation (UInt8) — 1 if this process is a part mutation.
  • total_size_bytes_compressed (UInt64) — The total size of the compressed data in the merged chunks.
  • total_size_marks (UInt64) — The total number of marks in the merged parts.
  • bytes_read_uncompressed (UInt64) — Number of bytes read, uncompressed.
  • rows_read (UInt64) — Number of rows read.
  • bytes_written_uncompressed (UInt64) — Number of bytes written, uncompressed.
  • rows_written (UInt64) — Number of rows written.
  • memory_usage (UInt64) — Memory consumption of the merge process.
  • thread_id (UInt64) — Thread ID of the merge process.
  • merge_type — The type of current merge. Empty if it's an mutation.
  • merge_algorithm — The algorithm used in current merge. Empty if it's an mutation.