Way to avoid hitting max field length. term_vectors vs offsets

Hi,

We are hitting errors "The length of [some_field] field of [some_doc] doc of [index] index has exceeded [10000000] - maximum allowed to be analyzed for highlighting. For large texts, indexing with offsets or term vectors is recommended!"

What's better way of storing large fields? I had checked 'offsets' (https://www.elastic.co/guide/en/elasticsearch/reference/current/index-options.html) But I don't understand how it would solve the problem. By it's explanation, when index_options is set to 'offsets', it seems like it'll index doc number, term freqs, positions, start and end character of offset. But the default is only doc number is indexed.

So how exactly does setting index_options to 'offsets' help here?

Thanks.