[Progress Communities] [Progress OpenEdge ABL] Forum Post: RE: Question about the performance of ABL queries resolved by multiple indexes

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Peter Judge

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As I recall, the compiler prefers indexes where *all* of the components are used over indexes where only _some_ of the components are used. I suspect you are correct but that's nothing I've had confirmed (or is in "the rules"). The paper at documentation.progress.com/.../database-index-usage.html is good, but it doesn't say that if you have 2 potential index matches, that the one with all satisfied fields will be chosen. Anecdotally it might do that. But you can disprove the theory easily enough too … so validation via COMPILE XREF or other means is really important.

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