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Wednesday, 8 January 2014

Pig Example - Loading Data From HBase

Pig Example - Loading Data From HBase


Background

This is just a simple pig script that use HBase as its data source. 

Column1 - timestamp - long
Column2 - composite numbers - bytearray
The Pig script loads in the data into the schema specified and then performs the various operations on it.  A UDF is used to convert the composite bytesarray into its two separate parts.  A param_file is also used to store the timestamps that will be tested. 

SmallIndex is the Column Family in this case.

hbase_iq1_pig is the name of the pig script.

Bash Command

pig -param_file paramfile.txt hbase_iq1_pig.pig

Pig Script

REGISTER ./ConvertCompositeKey.jar; 
DEFINE article allan.myudf.ConvertFirst();
DEFINE revision allan.myudf2.ConvertFirst(); 

in = LOAD 'hbase://Table' USING org.apache.pig.backend.hadoop.hbase.HBaseStorage('smallIndex:1' , '-loadKey true -caster HBaseBinaryConverter')
 AS (ts: long, comp:bytearray);
modify = FILTER in BY (((long)'$STARTDATE') <= ts) AND (((long)'$ENDDATE') >= ts);
titles = FOREACH modify GENERATE article(comp), revision(comp);
DUMP titles;

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