You need to work with formatted files for large entities.
Create a Record with all of the common fields you need, make string fields large enough for future
increases..
The first field of each record should be a SIZE file of the record and then a Version number, this can identify
the software version and the size of the chunk for other utilities to read it.
Some may even go as far as putting in a Header record that describes the Record layout, offsets into the
record and so on. Using this method you could dynamically create a hard record to fit the bill at runtime...
But in anycase, its faster to read in blocks as a complete record containing all your items in a raw format then it
is doing it all in string format line by line..
When you get done at the end of the day, you'll ask yourself why you didn't install SQLite!