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From Fabian Hueske <fhue...@gmail.com>
Subject Re: Expression DataSets
Date Mon, 19 Jan 2015 09:33:43 GMT
This is great!
Will this be exclusive for the Scala API or are we adding this (or similar)
functionality to the Java API as well?

2015-01-16 17:30 GMT+01:00 Stephan Ewen <sewen@apache.org>:

> Very exciting!
>
> This looks amazing. It almost looks like half a SQL interface ;-)
>
> On Fri, Jan 16, 2015 at 11:04 AM, Aljoscha Krettek <aljoscha@apache.org>
> wrote:
>
> > Hi,
> > I did some work recently on adding support for SQL-like queries on top
> > of DataSets. (This is known as "named datasets" in the jira issue:
> >
> >
> https://issues.apache.org/jira/browse/FLINK-947?jql=project%20%3D%20FLINK%20AND%20assignee%20%3D%20currentUser()%20AND%20resolution%20%3D%20Unresolved
> > ).
> >
> > I have support for filter, join, grouping and aggregation. I think the
> > basis is quite strong now but we can add support for more data types
> > and supported operations in the select expressions.
> >
> > Please have a look at my branch if you're interested:
> > https://github.com/aljoscha/flink/tree/linq You can look at the new
> > Expression ITCases to see what features are currently available and
> > how the interface is used. There are also two complete programs:
> > PageRankExpression and TPCHQuery3Expression.
> >
> > And now at last, a sneak peek at how the new interface is used:
> >
> > in.group('key).select('key, ('a + 10).avg + " the average", 'a.count)
> >
> > The notation 'foo are Scala symbols, I use them in the DSL to
> > reference named fields.
> >
> > Cheers,
> > Aljoscha
> >
>

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