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PowerTree for DOS

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  • Michael Mattias
    replied
    I presented some concepts in my article, "Database Indexing" which appeared in the July, 1995 issue of "BASICally Speaking." While I used the (free) "BT" index manager for the sample code, the text covers "index only" managers (such as PowerTree) in a pretty generic fashion.

    Reprints may be ordered ($4.00 US) from the publisher's web site http://www.infoms.com

    (I have no financial interest in reprint or subscription sales).


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    Michael Mattias
    Racine WI USA
    [email protected]

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  • Lance Edmonds
    replied
    All versions of PowerTREE work the same way - you pass a "key" string and a numeric "record number" value to PowerTREE and it stores the information. PowerTREE does nothing to the "record number" other than store and retrieve the value associated with a key.

    Therefore, what this value represents is up to you, the programmer. It could be a record number, or it could be a byte position within a file.

    With this in mind, indexing a file with variable-length records is simple - simply specify the byte (SEEK) location of the beginning of each "record" in the file as the "record number" value for PowerTREE.

    This makes it possible to index such a file with either binary or sequential file access, and use the SEEK function to retrieve the "record" location as you move through the file.


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    Lance
    PowerBASIC Support
    mailto:[email protected][email protected]</A>

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  • Philippe BROGNOLI
    Guest started a topic PowerTree for DOS

    PowerTree for DOS

    Could give some information about the way to use PowerTree (for dos)with file which have variable length record (like CSV file)
    Thanks for your help.
    Regards

    Philippe
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