map_serialization_version_* MergeTree table settings

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

map_serialization_version

Controls the serialization method used for Map columns.

Possible values:

• basic — Use the standard serialization for Map.
• with_buckets — Split keys into buckets during serialization. Using buckets improves reading individual keys from the Map.

The number of buckets in with_buckets serialization is determined by max_buckets_in_map and map_buckets_strategy.

map_serialization_version_for_zero_level_parts

This setting allows to specify a different serialization version of Map columns for zero level parts that are created during inserts. It can be useful to keep basic serialization for zero level parts to avoid performance degradation during inserts, while using with_buckets for merged parts.