Great!
As of your requirements there is very few business logic, and lot of
data entry.
With the estimation you gave about data size, I would try STON
straightforward to start prototyping.
see (for example)
http://www.jarober.com/blog/blogView?showComments=true&printTitle=ST_4U_389:_STON_Serializer&entry=3546585097
and EnterprisePharo.pdf, there is a chapter on STON (and lot of other
interesting chapters too).
Example: storing 1000 couples of string (a fake user/password list) of
about 23k of data on disk, takes 70 ms on my laptop.
Quite enough to start your development, as I said earlier no need for a
database from the start, make a DAL for your users storage that write
your user list with STON and modify it later to write to a db.
Simple: the write in itself is 3 lines of code.
| users fileStream |
users := (1 to: 1000)
collect: [ :i |
Array with: ('user',i asString)
with: ('pwd-',i asString) ].
[
fileStream := FileStream fileNamed: 'junk.txt'.
[ STON writer on: fileStream ; nextPut: users .
] ensure: [ fileStream close ].
] timeToRun inspect
HTH
Alain