Returns the rocksdb_level_metadata_t of the ith level from the specified
column family metadata.
Returns the rocksdb_column_family_metadata_t of the specified
column family.
Releases the specified rocksdb_level_metadata_t.
Returns the sst_file_metadata_t of the ith file from the specified level
metadata.
Releases the specified rocksdb_sst_file_metadata_t.
Returns the smallest key of the specified sst file.
The caller is responsible for releasing the returned memory.
Returns the smallest key of the specified sst file.
The caller is responsible for releasing the returned memory.