My user will never delete more than 5% of records: they enter
>invoices, customers, goods and packing runs periodically, largest
>tables are 250000 records, 30 MB
>
>Do you agree that in this case index on deleted() will decrease the speed of queries?

I've done some testing on a table about 500,000 recs, though only 20 MB. I've tested both optimizable and non-optimizable WHEREs, and gone so far as to close vfp between queries into cursor nofilter. Have vfp6 & Win98, 450 Mhz, 128 RAM.

The results are: I found no speed difference with or without Deleted() index for a table this size. Even the longest, toughest queries were extremely close in times for each method (longest queries were about 30 seconds).

So clearly, there's not any sense in having an index that doesn't provide any help.

However, Deleted() index may well help larger tables than this, I'm not saying that it won't...