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From Chen Li <che...@gmail.com>
Subject Re: Socket feed questions
Date Fri, 30 Oct 2015 16:58:59 GMT
@Heri: do you know where to find the test cases of AQL UDF, or have some
test cases of your own?  Jianfeng can start from there.

Chen

On Fri, Oct 30, 2015 at 12:30 AM, Heri Ramampiaro <heriram@gmail.com> wrote:

> Although I haven’t tested this (I have mostly used & created java-based
> UDFs),
> one can execute AQL calls from within a UDF. Feeds allows functions to
> execute arbitrary AQL statements (DDL, DMLs etc). I.e., I believe what
> you are trying to do is possible.
>
> For example you could do:
> (Given that you have a rec. type called Tweet, and a dataset
> ProcessedTweets
>
> create feed CoordTwitterFeed if not exists
> using “push_twitter" (("type-name"="Tweet”))
>         apply function find-intersection;
>
> (Here "find-intersection” is an AQL function that does the step specified
> under 2)).
>
> To do nr. 3 the easiest way is to have a modified version of the “hashTag”
> (let’s call this “tweetlocator”).  Java-based UDF (see my previous message
> with the
> TweetLib example). You can then connect this  as a secondary feed,
> connected to
> “CoordTwitterFeed”.
>
> E.g.:
> create secondary feed ProcessedTwitterFeed from feed CoordTwitterFeed
> apply function “tweelib#tweetlocator";
>
> Thereafter you can connect the feeds to appropriate datasets.
>
> (Since the find-intersection is an AQL function, you can also call
> “tweelib#tweetlocator”
> inside this function).
>
> Best,
> -heri
>
> > On Oct 30, 2015, at 12:18 AM, Young-Seok Kim <kisskys@gmail.com> wrote:
> >
> > I'm not sure whether the following UDF is possible or not, but hopefully
> it
> > is.
> > What we're trying to do is to have the following UDF.
> >
> > The UDF
> > 1) accepts an incoming tweet record through a feed job as an input and
> then
> > 2) takes a field, more specifically, coordinate field value from the
> tweet
> > record and sends a spatial-intersect query using the coordinate in order
> to
> > find out the corresponding county of the coordinates (we have created
> > AsterixDB instance which stores US county shapes records into a dataset
> and
> > created R-tree index on the polygon field of it, so the query will return
> > the county effectively using the R-tree index)
> > 3) creates a new tweet record consisting of the original record's fields
> +
> > the returned county value
> > 4) ingests to a tweet dataset in the AsterixDB instance.
> >
> > Can we have such an UDF?
> >
> > Best,
> > Young-Seok
> >
> >
> > On Thu, Oct 29, 2015 at 3:53 PM, Heri Ramampiaro <heriram@gmail.com>
> wrote:
> >
> >>>
> >>> 2. Can we use AQL function in those kind of feed UDFs?
> >>
> >> Can you give an example of what you are trying to do?
> >> I.e do you want to run an AQL inside a UDF or use an AQL function as a
> >> UDF connected to a running feed?
> >>
> >> -heri
>
>

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