How to reduce the size of an sqlite3 database for iphone?

Question

edit: many thanks for all the answers. Here are the results after applying the optimisations so far:

• Switching to sorting the characters and run l

Answer 1

As a text field, signature is currently using at least 26 * 8 bytes per entry (208 bytes) but if you were to pack the data into a bitfield, you could probably get away with only 3 bits per letter (reducing your maximum frequency per letter to 7). That would mean you could pack the entire signature in 26 * 3 bits = 78 bits = 10 bytes. Even if you used 4 bits per letter (for a maximum frequency of 15 per letter) you would only use 104 bits (13 bytes).

EDIT: After a bit more thought, I think 4 bits per letter (instead of 3) would be a better idea because it would make the binary math easier.

EDIT2: Reading through the docs on SQLite data types, it seems that you might be able to just make the "signature" field span 26 columns of type INTEGER and SQLite will do the right thing and only use as many bits as required to store the value.