Bug fix. The stored itemsize (string length) of the id column in a specific dataset that had interconnections across chromosome borders was too small. The dataset had one file per chromosome. Seems like the _get_max_str_lens_over_all_chromosomes() function doesn't do what the name implies if the chromosomes are located in different files. Fixed by updating the itemsize of the 'id' column if the new size is larger than the existing one. PS. The resize_table_columns() function wasn't called prior to this commit.