[Pharo-dev] Collection with spatiotemporal indexation - Ideas and discussions ?

Cédrick Béler cdrick65 at gmail.com
Sat Apr 23 13:29:15 EDT 2016


Hi Esteban,

Thanks a lot, I think I’ll try your History package, it seems to be a very good starting point (instead of hacking it myself).
I’ll try it soon.

Thanks for all the information ;)

Cheers,

Cédrik


> Le 23 avr. 2016 à 18:28, Esteban A. Maringolo <emaringolo at gmail.com> a écrit :
> 
> Maybe instead of having a Dictionary, you can use my History package [1].
> It allows you to add elements to "the history", and the History class
> will provide certain "lookup" strategies depending on how you want to
> query it.
> 
> It is a trimmed down version of an utility class I used for years in
> commercial products where the History contained thousands of elements.
> This version uses linear search, my previous implementation used
> binary search which was significantly faster with lots of elements in
> the collection.
> 
> Of course it doesn't solve your spatial queries needs, I don't know if
> there is something in Smalltalk for that other than the distance
> between two coordinates[2], PostgreSQL 9.2 has some support for
> "temporal" data/tables which you could combine with PostGIS if you
> need to combine a spatial query with a temporal one [3].
> 
> Regards,
> 
> [1] http://www.smalltalkhub.com/#!/~emaringolo/History
> [2] http://pastebin.com/ThKDXCKK
> [3] http://clarkdave.net/2015/02/historical-records-with-postgresql-and-temporal-tables-and-sql-2011/
> Esteban A. Maringolo
> 
> 
> 2016-04-23 12:13 GMT-03:00 Cédrick Béler <cdrick65 at gmail.com>:
>> 
>> 
>> Sure, but 1) that's not a lot
>> 
>> 2) do you even know if you need interactive stuff or if batch processing is
>> ok?
>> 
>> 
>> interactive I would say… but hard to be certain right now as it depends on
>> design choices… do we cache ? do we aggregate past data ? extra indexes ?
>> I’ll see later.
>> I want something simple, keep everything… and query according to time
>> interval, areas (contexts)…
>> 
>> But yes for now this is pointless to look for something optimal and I’ll use
>> a dictionary as it will be small at start.
>> 
>> Cheers,
>> 
>> Cédrik
>> 
>> 
>> 
>> 
>> --
>> Damien Pollet
>> type less, do more [ | ] http://people.untyped.org/damien.pollet
>> 
>> 
> 




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