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Editorial Team
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Asked: 2026-05-24T20:58:11+00:00

I need to return all the entries in my database that are fairly close

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I need to return all the entries in my database that are fairly close to a given point. At the moment I am doing this (in the WHERE section):

OR (    
    (Addresses.Latitude IS NOT NULL)
    AND (Addresses.Longitude IS NOT NULL)
    AND ( Abs(Addresses.Latitude - @SearchInLat)  < 0.5)
    AND ( Abs(Addresses.Longitude - @SearchInLng) < 0.5)
)

I am doing manhattan distance rather than cartesian distance as my database has a large number of records, and calculating square roots is slow.

I’m pretty new to SQL databases, but I remember reading that it is considered very bad for efficiency to have functions inside SELECT procudures. Does this even apply for really simple functions such as taking the absolute value? Is something like:

OR (    
    (Addresses.Latitude IS NOT NULL)
    AND (Addresses.Longitude IS NOT NULL)
    AND ( (Addresses.Latitude - @SearchInLat)  < 0.5)
    AND ( (Addresses.Latitude - @SearchInLat)  > -0.5)
    AND ( (Addresses.Longitude - @SearchInLng) < 0.5)
    AND ( (Addresses.Longitude - @SearchInLng) > -0.5)
)

a better solution?

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1 Answer

  1. Editorial Team

    It is often not very efficient to have functions run on the data being returned – as in the case of your ABS. I don’t think you’re in any trouble in this case, however. You could avoid the use of the function by trying something like:

    OR (    
    (Addresses.Latitude IS NOT NULL)
    AND (Addresses.Longitude IS NOT NULL)
    AND ( (Addresses.Latitude - @SearchInLat) BETWEEN -0.5 AND 0.5)
    AND ( (Addresses.Longitude - @SearchInLng) BETWEEN -0.5 AND 0.5)
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