max_parts_* MergeTree table settings

These settings are available in system.merge_tree_settings and are autogenerated from ClickHouse source.

max_parts_in_total

If the total number of active parts in all partitions of a table exceeds the max_parts_in_total value INSERT is interrupted with the Too many parts (N) exception.

Possible values:

• Any positive integer.

A large number of parts in a table reduces performance of ClickHouse queries and increases ClickHouse boot time. Most often this is a consequence of an incorrect design (mistakes when choosing a partitioning strategy - too small partitions).

max_parts_to_merge_at_once

Max amount of parts which can be merged at once (0 - disabled). Doesn’t affect OPTIMIZE FINAL query.