Crystal will ALWAYS use tmp disk space as storage, and it's not always very good a cleaning up after itself. Look at the C:\Documents and Settings\<user ID>\Local Settings\Temp folder (you may have to set Windows Explorer to show hidden folders because Local Settings is usually hidden.) You want to clear out this folder on a regular basis to recover disk space.
When you're working with large datasets, you want to do as much of the work as possible on the database server. This means:
1. Turn on "Use Indexes or Server for Speed" and "Perform Grouping on Server" in the Crystal Options screen and "Use Indexes or Server for Speed" in the report Options screen.
2. Group on fields not on formulas. If you can't do this, you may want to consider using a command instead of tables (if your database will allow it.)
3. Select based on fields, not formulas. If you can't do this, you may want to consider using a command instead of tables (if your database will allow it.)
The reason for items 2 and 3 is that if you use formulas, Crystal will will bring all of the data to the workstation and do its filtering/grouping in memory there instead of doing it on the server. This also assumes that you're using a client/server database like MS SQL Server, Oracle, etc and not a file based database like MS Access, Paradox, dBase, etc.
-Dell