SQLite: updating string values I couldn't find any answer for my question so I'm writing.

Are there any restrictions for updating strings in SQLite database ?
I'm wondering if any new value is written into database file there could be problem for strings of different length. Isn't it ?
I anticipate that I update strings in database and their length will be different.
In such situation should I store them into files and store only file names into database ?
Please give me some optimization tips.
SQLite can resize field values and records dynamically, so there are no restrictions on updating strings (except for the normal limits).