These settings are available in system.merge_tree_settings and are autogenerated from ClickHouse source.
marks_compress_block_size
Type
NonZeroUInt64
Default
65536
Mark compress block size, the actual size of the block to compress.
marks_compression_codec
Type
String
Default
ZSTD(3)
Compression encoding used by marks, marks are small enough and cached, so the default compression is ZSTD(3).