R
Rob Fitzpatrick
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> What to do with the word indexes (_Wordidx eq 1)? >BUT biggest Problem is, that this reports redundant Indexes, even if it is a single-field index and a multi-field index starting with same field. But this is not redundant, as multi-field indexes will not be used for selecting multiple Indexes for a query. These points both relate to the problem definition. I'm not sure that code will address this need 100%, nor that everyone will agree on one definition of a "redundant index". Maybe the best that a program can do is make a list of candidates to be manually evaluated. So what do people think is a definition of a "redundant index"? Starting with what I wrote above: What would you add or change in this definition to make it better? An index I is redundant if there exists an index I' on the same table that satisfies the following conditions: - the components of I are the leading components of I', in the same order - the sort order of the components of I (ASC or DESC) are the same in I' - it is not the case that I is unique and I' is non-unique E.g.: - either I and I' are both word indexes or neither are word indexes - What about "abbreviated" indexes, where the two indexes share the same component list but one is abbreviated and the other is not? Would they be non-redundant?
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