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Re: [Format] Pointer types / span types


Actually, "pointer type" might just be another name for "dictionary type".

Regards

Antoine.


Le 30/04/2018 à 22:08, Antoine Pitrou a écrit :
> 
> Hi,
> 
> Today I got the opportunity to talk with Jim Pivarski, the main
> developer on the OAMap project (*).  Under the hood, he is doing
> something not unlike the Arrow representation of nested arrays: he
> stores and processes structured data as linear arrays, allowing very
> fast processing on seemingly irregular data (in Array parlance, think
> something like lists of lists of structs).  It seems that OAMap data
> requires two kinds of logical types that Arrow misses :
> 
> - a pointer type, where a physical array of ints is used to represent
> indices into another array (the logical value being of course the value
> pointed to)
> - a span type, where two physical arrays of ints are used to represent
> start and stop indices into another array (the logical value being the
> list of values delimited by the start / stop indices)
> 
> Did such a feature request already come by?  Is this something we should
> add to our roadmap or future wishlist?
> 
> (*) https://github.com/diana-hep/oamap
> 
> Regards
> 
> Antoine.
>