I am using Pig 0.5 version. We don't have plans to upgrade it to a newer version. But the problem I have is the script runs for some files(both larger and smaller than the ones mentioned) but not for this particular one. I get "GC overhead limit" Error. Thanks Sri
-----Original Message----- From: Thejas M Nair [mailto:[email protected]] Sent: Monday, March 14, 2011 4:18 PM To: [email protected]; Paltheru, Srikanth Subject: Re: Problems with Join in pig What version of pig are you using ? There have been some memory utilization fixes in 0.8 . For this use case, you can also use the new scalar feature in 0.8 - http://pig.apache.org/docs/r0.8.0/piglatin_ref2.html#Casting+Relations+to+Sc alars . That query plan will be more efficient. You might want to build a new version of pig from svn 0.8 branch because there have been some bug fixes after the release - svn co http://svn.apache.org/repos/asf/pig/branches/branch-0.8 cd branch-0.8 ant -Thejas On 3/14/11 1:40 PM, "Paltheru, Srikanth" <[email protected]> wrote: > The following pig script runs fine without the 2GB memory setting (see > in yellow). But fails with memory setting. I am not sure what's > happening. It's a simple operation of joining one tuple(of 1 row) with the > other tuple. > Here is what I am trying to do: > > 1. grouping all SELECT HIT TIME DATA into a single tuple by doing a > GROUP ALL. > 2. getting the min and max of that set and putting it into MIN HIT DATA. > This is a tuple with a single row. > 3. then grouping SELECT MAX VISIT TIME DATA by visid, 4. then > generating DUMMY_KEY for every row, along with MAX of start time. > 5. then try to join the single tuple in 2 with all tuples generated > in 4 to get a min time and a max time > > Code: > Shell prompt: > ## setting heap size to 2 GB > PIG_OPTS="$PIG_OPTS -Dmapred.child.java.opts=-Xmx2048m" > export PIG_OPTS > > Pig/Grunt > > RAW_DATA = LOAD > '/omniture_test_qa/cleansed_output_1/2011/01/05/wdgesp360/wdgesp360_20 > 11-01-05 > *.tsv.gz' USING PigStorage('\t'); > FILTER_EXCLUDES_DATA = FILTER RAW_DATA BY $6 <= 0; SELECT_CAST_DATA = > FOREACH FILTER_EXCLUDES_DATA GENERATE 'DUMMYKEY' AS > DUMMY_KEY,(int)$0 AS hit_time_gmt, (long)$2 AS visid_high, (long)$3 AS > visid_low, (chararray)$5 AS truncated_hit; SELECT_DATA = FILTER > SELECT_CAST_DATA BY truncated_hit =='N'; --MIN AND MAX_HIT_TIME_GMT > FOR THE FILE/SUITE SELECT_HIT_TIME_DATA = FOREACH SELECT_DATA GENERATE > (int)hit_time_gmt; GROUPED_ALL_DATA = GROUP SELECT_HIT_TIME_DATA ALL > PARALLEL 100; MIN_HIT_DATA = FOREACH GROUPED_ALL_DATA GENERATE > 'DUMMYKEY'AS > DUMMY_KEY,MIN(SELECT_HIT_TIME_DATA.hit_time_gmt) AS > MIN_HIT_TIME_GMT,MAX(SELECT_HIT_TIME_DATA.hit_time_gmt) AS > MAX_HIT_TIME_GMT; ---MAX_VISIT_START_TIME BY VISITOR_ID > SELECT_MAX_VISIT_TIME_DATA = FOREACH SELECT_DATA GENERATE > visid_high,visid_low,visit_start_time_gmt; > GROUP_BY_VISID_MAX_VISIT_TIME_DATA = GROUP SELECT_MAX_VISIT_TIME_DATA > BY > (visid_high,visid_low) PARALLEL 100; > MAX_VISIT_TIME = FOREACH GROUP_BY_VISID_MAX_VISIT_TIME_DATA GENERATE > 'DUMMYKEY' AS DUMMY_KEY,FLATTEN(group.visid_high) AS > visid_high,FLATTEN(group.visid_low) AS visid_low, > MAX(SELECT_MAX_VISIT_TIME_DATA.visit_start_time_gmt) AS > MAX_VISIT_START_TIME; JOINED_MAX_VISIT_TIME_DATA = COGROUP > MAX_VISIT_TIME BY DUMMY_KEY OUTER,MIN_HIT_DATA BY DUMMY_KEY OUTER > PARALLEL 100; MIN_MAX_VISIT_HIT_TIME = FOREACH > JOINED_MAX_VISIT_TIME_DATA GENERATE > FLATTEN(MAX_VISIT_TIME.visid_high),FLATTEN(MAX_VISIT_TIME.visid_low),F > LATTEN(M > AX_VISIT_TIME.MAX_VISIT_START_TIME),FLATTEN(MIN_HIT_DATA.MIN_HIT_TIME_ > GMT),FLA > TTEN(MIN_HIT_DATA.MAX_HIT_TIME_GMT); > DUMP MIN_MAX_VISIT_HIT_TIME; > > > Can any one please guide me through this problem? > Thanks > Sri >
