map_serialization_version
Controls the serialization method used forMap 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.
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 ofMap 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.