'm importing fairly large fixed-length ASCII data files into SQL7. The ASCII data total about 5GB; I estimate the final SQL7 database size to be 7-10GB. The data will be imported non-logged using bcp, BULK INSERT and/or DTS as appropriate.

- Is it a good idea (or necessary) to pre-define the size of the target database (e.g. 10GB)?

Yes


- To keep database size down I'm planning to use smalldatetime, smallmoney etc. where appropriate. Are there any drawbacks to this when queries are run from common client side tools (Access, Visual FoxPro etc.)?

No


- This is a research database, loaded once then queried many times. I'm planning to use char columns instead of nchar to save size, but does char offer any query performance advantage compared to varchar? The character columns are pretty much completely filled, so varchar would save very little, or no, space.

If the value medium fills up the field for 90% use CHAR, otherwise use Trimmed VARCHAR.

Fabio