preferred_block_size_bytes
This setting adjusts the data block size for query processing and represents additional fine-tuning to the more rough ‘max_block_size’ setting. If the columns are large and with ‘max_block_size’ rows the block size is likely to be larger than the specified amount of bytes, its size will be lowered for better CPU cache locality.preferred_max_column_in_block_size_bytes
Limit on max column size in block while reading. Helps to decrease cache misses count. Should be close to L2 cache size.preferred_optimize_projection_name
If it is set to a non-empty string, ClickHouse will try to apply specified projection in query. Possible values:- string: name of preferred projectio