It doesn't make any difference for queries if index is set or not. It does matter for VFP commands with FOR clause because they have to respect currently set index order. It may slow such commands significantly.

>We all know that VFP uses index tags (existing or created) for Rushmore optimization, but I seem to remember that having an index tag active defeats optimization. In other words, the Fox wants to have an index available, but not used.
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>I've been trying to remember where I read that, but it has been a few years, and I've slept since then. Does anyone else remember this?