You need to double the size of the index. You now need an index with punctuation and without punctuation. Previously if a document contained "(hello" it would

You need to double the size of the index. You now need an index with punctuation and without punctuation. Previously if a document contained "(hello" it would just be stored in the index once: as "hello". With this change, it needs to be stored in the index twice, as "(hello" and "hello", so that people searching either term can find it.