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Pig, mail # user - CROSS/Self-Join Bug - Please Help :(


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Re: CROSS/Self-Join Bug - Please Help :(
Russell Jurney 2013-12-04, 22:06
If you store immediately after the CROSS, it works. If you do another
FOREACH/GENERATE, etc. it does not.
On Wed, Dec 4, 2013 at 1:41 PM, Pradeep Gollakota <[EMAIL PROTECTED]>wrote:

> I tried to following script (not exactly the same) and it worked correctly
> for me.
>
> businesses = LOAD 'dataset' using PigStorage(',') AS (a, b, c,
> business_id: chararray, lat: double, lng: double);
> locations = FOREACH businesses GENERATE business_id, lat, lng;
> STORE locations INTO 'locations.tsv';
> locations2 = LOAD 'locations.tsv' AS (business_id, lat, long);
> loc_com = CROSS locations2, locations;
> dump loc_com;
>
> I’m wondering your problem has something to do with the way that the
> JsonStorage works. Another thing you can try is to load ‘locations.tsv’
> twice and do a self-cross on that.
>
>
> On Wed, Dec 4, 2013 at 1:21 PM, Russell Jurney <[EMAIL PROTECTED]
> >wrote:
>
> > I have this bug that is killing me, where I can't self-join/cross a
> dataset
> > with itself. Its blocking my work :(
> >
> > The script is like this:
> >
> > businesses = LOAD
> > 'yelp_phoenix_academic_dataset/yelp_academic_dataset_business.json' using
> > com.twitter.elephantbird.pig.load.JsonLoader() as json:map[];
> >
> > /* {open=true, neighborhoods={}, review_count=14, stars=4.0, name=Drybar,
> > business_id=LcAamvosJu0bcPgEVF-9sQ, state=AZ, full_address=3172 E
> Camelback
> > Rd
> > Phoenix, AZ85018, categories={(Hair Salons),(Hair Stylists),(Beauty &
> > Spas)}, longitude=-112.0131927, latitude=33.5107772, type=business,
> > city=Phoenix} */
> > locations = FOREACH businesses GENERATE $0#'business_id' AS business_id,
> >                                       $0#'longitude' AS longitude,
> >                                       $0#'latitude' AS latitude;
> > STORE locations INTO 'yelp_phoenix_academic_dataset/locations.tsv';
> > locations_2 = LOAD 'yelp_phoenix_academic_dataset/locations.tsv' AS
> > (business_id:chararray, longitude:double, latitude:double);
> > location_comparisons = CROSS locations_2, locations;
> >
> > distances = FOREACH businesses GENERATE locations.business_id AS
> > business_id_1,
> >                                         locations_2.business_id AS
> > business_id_2,
> >
> udfs.haversine(locations.longitude,
> >
>  locations.latitude,
> >
> >  locations_2.longitude,
> >
> >  locations_2.latitude) AS distance;
> > STORE distances INTO 'yelp_phoenix_academic_dataset/distances.tsv';
> >
> >
> > I have also tried converting this to a self-join using JOIN BY '1', and
> > also locations_2 = locations, and I get the same error:
> >
> > *org.apache.pig.backend.executionengine.ExecException: ERROR 0: Scalar
> has
> > more than one row in the output. 1st :
> > (rncjoVoEFUJGCUoC1JgnUA,-112.241596,33.581867), 2nd
> > :(0FNFSzCFP_rGUoJx8W7tJg,-112.105933,33.604054)*
> >
> > at org.apache.pig.impl.builtin.ReadScalars.exec(ReadScalars.java:111)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:336)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:438)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.getNext(PhysicalOperator.java:347)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:378)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNext(POForEach.java:298)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.runPipeline(PigGenericMapBase.java:283)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:278)
> >
> > at
> >
> >
> org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:64)

Russell Jurney twitter.com/rjurney [EMAIL PROTECTED] datasyndrome.com