Rushmore "lives" in the VFP core, which is also a part of the runtime files. But it is not really "rocket science", it is only a set of algorithms which evaluate all available indexes and choose which, if any, indexes will speed up the search, and how to use these indexes optimally. I don't think it would be that difficult to duplicate this functionality?


>Tore:
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>Yes, but my question was "where does Rushmore live?" Is it contained in the index files or is it mainly in the VFP runtime libraries or maybe in both. If it is the all in the index, then taking advantage of it from something like VFP.NET should be trivial. If not, it would be a huge and possibly impossible undertaking. And there might be some intellectual property and/or patent infingment implications as well, which would stop anyone from reverse-engineering it to another VFP -like implementation. However, with all these great, fast (and free!) database backends (Postgres, MySQL, Firebird) now available, this shouldn't be a big deal anyway.
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>Pertti
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>>>>What I've been wondering about: How about Rushmore? Or more precisely, how about the typically superb performance when querying? Do you think you'll gonna need the LINQ facilities that are currently implemented? (I'm assuming here that database features in VB.NET will show a similar speed after the LINQ project has finished.)
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>>>I maybe wrong about this, but isn't Rushmore all in the VFP index files?
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>>>Pertti
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>>To put it short, Rushmore is the name of the technology which optimizes the use of the available indexes.
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>>From http://www.foxprohistory.org/rushmore.htm: Rushmore is a data access technique that permits sets of records to be accessed very efficiently. Rushmore query optimization uses indexes efficiently to quickly find a set of records. It is used on queries that involve restrictions on multiple-indexed fields. Rushmore is an exclusive technology for rapidly selecting sets of records from tables. It can reduce query response times from hours or minutes to seconds.
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>>The legendary data access performance in FoxPro stems from its Rushmore query optimization and use of fixed length storage of data. Rushmore creates bit-mapped indexes that allow the engine to very quickly determine whether each row in a table meets a criteria and should therefore be included in a query's result set. Fixed width storage of data ensures that a field will be in the same location from row to row, making that field easier to locate.
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>>Starting with the Rushmore query technology in the Visual FoxPro 2.0 release, FoxPro's primary attraction has been its fast data engine. It doesn't seem to have lost that edge over the years: posted reports on the newsgroups claim the new release of Visual FoxPro is twice as fast as SQL Server, for 50 users or less.