Hello Ryan,

On Mon, Feb 4, 2019 at 10:52 AM Ryan Blue <rb...@netflix.com> wrote:
>
> Andrew, can you give us more information about why partitioning the output 
> data doesn't work for your use case?
>
> It sounds like all you need to do is to create a table partitioned by A and 
> B, then you would automatically get the divisions you want. If what you're 
> looking for is a way to scale the number of combinations then you can use 
> formats that support more partitions, or you could sort by the fields and 
> rely on Parquet row group pruning to filter out data you don't want.
>

TBH, I don't understand what that would look like in pyspark and what
the consequences would be. Looking at the docs, it doesn't appear to
be the syntax for partitioning on a condition (most of our conditions
are of the form 'X > 30'). The use of Spark is still somewhat new in
our field, so it's possible we're not using it correctly.

Cheers
Andrew

> rb
>
> On Mon, Feb 4, 2019 at 8:33 AM Andrew Melo <andrew.m...@gmail.com> wrote:
>>
>> Hello
>>
>> On Sat, Feb 2, 2019 at 12:19 AM Moein Hosseini <moein...@gmail.com> wrote:
>> >
>> > I've seen many application need to split dataset to multiple datasets 
>> > based on some conditions. As there is no method to do it in one place, 
>> > developers use filter method multiple times. I think it can be useful to 
>> > have method to split dataset based on condition in one iteration, 
>> > something like partition method of scala (of-course scala partition just 
>> > split list into two list, but something more general can be more useful).
>> > If you think it can be helpful, I can create Jira issue and work on it to 
>> > send PR.
>>
>> This would be a really useful feature for our use case (processing
>> collision data from the LHC). We typically want to take some sort of
>> input and split into multiple disjoint outputs based on some
>> conditions. E.g. if we have two conditions A and B, we'll end up with
>> 4 outputs (AB, !AB, A!B, !A!B). As we add more conditions, the
>> combinatorics explode like n^2, when we could produce them all up
>> front with this "multi filter" (or however it would be called).
>>
>> Cheers
>> Andrew
>>
>> >
>> > Best Regards
>> > Moein
>> >
>> > --
>> >
>> > Moein Hosseini
>> > Data Engineer
>> > mobile: +98 912 468 1859
>> > site: www.moein.xyz
>> > email: moein...@gmail.com
>> >
>>
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>
>
> --
> Ryan Blue
> Software Engineer
> Netflix

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