Jason, Do you want to open a JIRA and contrib your map_explode function to Hive? That will be greatly appreciated.
Zheng On Fri, Feb 19, 2010 at 2:49 PM, Yongqiang He <heyongqi...@software.ict.ac.cn> wrote: > Hi Jason, > > This is a known bug, see https://issues.apache.org/jira/browse/HIVE-1056 > > You can first disable ppd with “set hive.optimize.ppd=false;” > > Thanks > Yongqiang > On 2/19/10 2:23 PM, "Jason Michael" <jmich...@videoegg.com> wrote: > > I’m currently running a hive build from trunk, revision number 911889. I’ve > built a UDTF called map_explode which just emits the key and value of each > entry in a map as a row in the result table. The table I’m running it > against looks like: > > hive> describe mytable; > product string from deserializer > ... > interactions map<string,int> from deserializer > > If I use the map_explode in the select clause, I get the expected results: > > hive> select map_explode(interactions) as (key, value) from mytable where > day = '2010-02-18' and hour = 1 limit 10; > ... > OK > invite_impression 1 > invite_impression 1 > invite_impression 1 > invite_impression 1 > rollout 12 > invite_impression 1 > invite_impression 1 > invite_impression 1 > rollout 4 > invite_impression 1 > Time taken: 22.11 seconds > > However, if I try to use LATERAL JOIN to relate the exploded values back to > the parent table, like so: > > hive> select product, key, sum(value) from mytable LATERAL VIEW > map_explode(interactions) interacts as key, value where day = '2010-02-18' > and hour = 1 group by product, key; > > I get the following error: > > FAILED: Unknown exception: null > > Looking in hive.log, I see the follow stack trace: > > 2010-02-19 14:15:17,215 ERROR ql.Driver (SessionState.java:printError(255)) > - FAILED: Unknown exception: null > java.lang.NullPointerException > at > org.apache.hadoop.hive.ql.ppd.ExprWalkerProcFactory$ColumnExprProcessor.process(ExprWalkerProcFactory.java:87) > at > org.apache.hadoop.hive.ql.lib.DefaultRuleDispatcher.dispatch(DefaultRuleDispatcher.java:89) > at > org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.dispatch(DefaultGraphWalker.java:89) > at > org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.walk(DefaultGraphWalker.java:129) > at > org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.startWalking(DefaultGraphWalker.java:103) > at > org.apache.hadoop.hive.ql.ppd.ExprWalkerProcFactory.extractPushdownPreds(ExprWalkerProcFactory.java:273) > at > org.apache.hadoop.hive.ql.ppd.OpProcFactory$DefaultPPD.mergeWithChildrenPred(OpProcFactory.java:317) > at > org.apache.hadoop.hive.ql.ppd.OpProcFactory$DefaultPPD.process(OpProcFactory.java:258) > at > org.apache.hadoop.hive.ql.lib.DefaultRuleDispatcher.dispatch(DefaultRuleDispatcher.java:89) > at > org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.dispatch(DefaultGraphWalker.java:89) > at > org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.walk(DefaultGraphWalker.java:129) > at > org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.startWalking(DefaultGraphWalker.java:103) > at > org.apache.hadoop.hive.ql.ppd.PredicatePushDown.transform(PredicatePushDown.java:103) > at > org.apache.hadoop.hive.ql.optimizer.Optimizer.optimize(Optimizer.java:74) > at > org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.analyzeInternal(SemanticAnalyzer.java:5758) > at > org.apache.hadoop.hive.ql.parse.BaseSemanticAnalyzer.analyze(BaseSemanticAnalyzer.java:125) > at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:304) > at org.apache.hadoop.hive.ql.Driver.run(Driver.java:377) > at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:138) > at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:197) > at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:303) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) > at java.lang.reflect.Method.invoke(Method.java:597) > at org.apache.hadoop.util.RunJar.main(RunJar.java:156) > > I peeked at ExprWalkerProcFactory, but couldn’t readily see what was causing > the problem. Any ideas? > > Jason > -- Yours, Zheng
