Hi Jos,
>
>In all my years of using VFP I cannot remember ever using a Double type field in a table. Now I need to store numeric values which exceed 10 digits before the decimal point and up to 4 digits after the decimal point giving me a numeric field of 15,4. However, I notice that a double field type takes up 8 bytes which would be less than a numeric field catering for 15,4. Are there any obvious problems or issues to be aware of if I convert to using doubles as a field type, any things to watch or check for?

As you are near the vfp limit of precision for numeric data perhaps a switch to currency would be better:
also 8 byte storage, but as it is an 8-byte longlong int with artificial fraction perhaps better suited to your needs.
Depends a lot on what you want to do with it besides table storage ;-)

regards

thomas