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results will come back.
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<h3>3.3 Roundoff Error</h3>
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By default, coordinates are stored in an R*Tree using 32-bit floating
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point values. When a coordinate cannot be exactly represented by a
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32-bit floating point number, the lower-bound coordinates are rounded down
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and the upper-bound coordinates are rounded up. Thus, bounding boxes might
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be slightly larger than specified, but will never be any smaller. This
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is exactly what is desired for doing the more common "overlapping" queries
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where the application wants to find every entry in the R*Tree that overlaps
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a query bounding box. Rounding the entry bounding boxes outward might cause a
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few extra entries to appears in an overlapping query if the edge of the
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entry bounding box corresponds to an edge of the query bounding box. But
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the overlapping query will never miss a valid table entry.
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<p>However, for a "contained-within" style query, rounding the bounding
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boxes outward might cause some entries to be excluded from the result set
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if the edge of the entry bounding box corresponds to the edge of the query
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bounding box. To guard against this, applications should expand their
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contained-within query boxes slightly (by 0.000012%) by rounding down the
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lower coordinates and rounding up the top coordinates, in each dimension.
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<h2>4.0 Using R*Trees Effectively</h2>
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