the CompressionCodecId of default compression scheme (Constant.DEFAULT_CODEC)
The case of codec > MAX_ID should ideally be error but due to backward compatibility the stats row does not have any header to determine compression or not so can fail in rare cases if first integer is a negative value.
The case of codec > MAX_ID should ideally be error but due to backward compatibility the stats row does not have any header to determine compression or not so can fail in rare cases if first integer is a negative value. However it should never be match with the IDs here because negative of codecId which is written are -1, -2, -3 resolve to 0xfffffff... which should never happen since nullCount fields are non-nullable (for not updated columns we keep -1 in null count) in the UnsafeRow created, so bitset cannot have 'ff' kind of patterns.
Compression schemes supported by snappy-store.