I can reproduce this in 0.6, and it appears to have nothing to do with your
data or with the DUMP operator -- a simple "explain" on D causes the same
problem. Looks like there is something wrong with how the query plan gets
compiled:
Caused by: java.lang.NullPointerException
at org.apache.pig.impl.plan.OperatorPlan.add(OperatorPlan.java:152)
at
org.apache.pig.impl.logicalLayer.parser.QueryParser.generateStorePlan(QueryParser.java:128)
at org.apache.pig.PigServer.store(PigServer.java:552)
... 7 more
Haven't tried on 0.7
-D
On Mon, Jun 7, 2010 at 5:10 AM, Alexander Schätzle <
[email protected]> wrote:
> I exchanged the FILTER statement by a SPLIT:
>
> SPLIT C into D if var3 is null, E if var3 is not null;
>
> Now, this works!
> Obviously there is a problem with null-values in the FILTER statement.
> Does anybody know what's the problem?
>
> Cheers,
> Alex
>
>
>
> ________________________________
> Von: Rekha Joshi <[email protected]>
> An: "[email protected]" <[email protected]>
> Gesendet: Montag, den 7. Juni 2010, 10:22:19 Uhr
> Betreff: Re: Unable to store alias
>
> Offhand I think its dump faulty behavior after join combined with datatype
> misinterpretation, you can use store and that might work. However I would
> try using a foreach generate stmt after C and then filter..
>
> D = foreach C generate $0 as fvar1, $1 as fvar2, (chararray)$2 as fvar3;
> E = filter D by fvar3 is null;
> Dump E; //verify result at null
> E = filter D by fvar3 is not null;
> Dump E; //Verify results for not null
>
> Cheers,
> /R
>
> On 6/7/10 12:57 PM, "Alexander SchÀtzle" <[email protected]>
> wrote:
>
> Hi all,
>
> my script looks like this:
>
> A = LOAD 'left_rel.txt' AS (var1, var2);
> B = LOAD 'right_rel.txt' AS (var1, var3);
> C = JOIN A BY var1 LEFT OUTER, B BY var1;
> D = FILTER C BY $2 is null;
> DUMP D;
>
> But when I dump D I get the error "Unable to store alias D".
> I suppose there is something going wrong with the Filter vor null-values
> (is not null also doesn't work).
> What I want to do is to filter for the tuples in A which do not find a Join
> partner in B
> Input files are attached.
>
> Does anybody know what's going on and how to fix this?
> By the way, I'm using Cloudera Distribution for Hadoop 3 Beta with pig
> 0.5.0.
>
> Thx in advance,
> Alex
>
>
