Sure you hash and stir that, when searching for a particular lat/long
combination you has entry and search
This will not help in distance calculations
How about this for a create a concatenated key that has two parts for each
Named LatKey
Lat_before decimal
Lat_after decimal
LongKey
Long_before decimal
long_after decimal
do queries
and process using fields that contain the entire lat and long as a real
Regards
Chuck
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> On Apr 14, 2020, at 3:24 PM, John J Foster via 4D_Tech <[email protected]>
> wrote:
>
> Hi Arnaud,
>
> Hmmm...
>
> I think I would like the data to be obvious to my eyes when I look at it.
>
> My initial goal was simply to be able to match up a location with a missing
> Olson Timezone ID. Import the data, fix the data in the much larger db, and
> then export it back out to reimport into it’s source db. The imported data
> will always be a much smaller subset (at this time).
>
> Then I realized that having the ability to do a radial search would be nice.
> Show me all cities within 4 minutes from this longitude/latitude. So being
> able to search quickly is important.
>
> So all of this work is for those two needs.
>
> Anyway, appreciate,
> John…
>
>
>>> Le 13 avr. 2020 à 23:51, John J Foster via 4D_Tech <[email protected]
>>> <mailto:[email protected]>> a écrit :
>>>
>>> Hey Bernard,
>>>
>>> I would use text values if I didn’t think I needed to do range searches.
>>> It’s not a “live” db so I can play and experiment to my hearts content.
>>
>> Considering 5 million pairs of long/lat values is a lot, I'd first try to
>> see if I can store values in a different field type than a real. Examples:
>> - integer or longint : multiply by 10^x and remove decimals; depends on the
>> number of digits you need to keep (example, Lat,Long=48.862725,2.28759
>> becomes 48862725,2287590)
>> - uuid: no limit about the encoded number, but I don't know if performances
>> are better than real
>>
>> --
>> Arnaud de Montard
>
>
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