Look, Rightnow, i test one dbf file with 1,500,000.00 records. I do this:
i Create one Tag: index on codigo for !delete() tag i001, and this tag constantly will be part the my dbf file. i mean, i will never return to creat it, and i will require after in other aplication. The affair, is that the tag to exist, it will to serve, for find records.

After, make de Query and all rigth

you test and warn me, What happens it?