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Posted by Erland Sommarskog on 06/08/07 21:07
Jeff Kish (kishjjrjj@charter.net) writes:
> the data represents coordinates on images that can vary vastly in
> scale and precision.
> The primary key well... each row in the table represents a text
> display on an image.. the row has columns for:
> book
> page
> label
> xcoord
> ycoord
> because the same label can appear several times on one page in a book,
> the coords are included.
>
> one page might vary from -1.234565 to 1.3234343 in extents, placing
> all coordinates in that range, and another might be a different type
> of image and range from -10245 to 10245.
Could you have coordinates that are 1E12 or 1E-12 as well? I would
expect that is after all some practical limit. In this case you could use
something like decimal(20,10). Or may be varchar is an alternative? I
would definitely avoid float.
Yet an alternative is some roll-your-own decimal. That is, you would
save the coordinates as integer, and you would store the scale separately,
possibly in a table with the page as key.
--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se
Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx
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