我有一个蜂巢表，基本上是网站上的互动。我需要找到最后一次交互具有某些值的x，y和z的会话数。我得到一个NullPointerException，我无法确定原因。
（注意：名称已被更改以保护无辜者。）
SELECT COUNT(1)
FROM a_table
WHERE ds >= 'a_start_date' AND ds <= 'an_end_date'
GROUP BY session, request_started, x, y, z
HAVING MAX(array(request_started, x))[1] = 'a value'
AND MAX(array(request_started, y))[1] = 'another value'
AND MAX(array(request_started, z))[1] IN ('value 1', 'value 2');
FAILED: Hive Internal Error: java.lang.NullPointerException(null)
java.lang.NullPointerException
at org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc.newInstance(ExprNodeGenericFuncDesc.java:153)
at org.apache.hadoop.hive.ql.parse.TypeCheckProcFactory$DefaultExprProcessor.getXpathOrFuncExprNodeDesc(TypeCheckProcFactory.java:634)
at org.apache.hadoop.hive.ql.parse.TypeCheckProcFactory$DefaultExprProcessor.process(TypeCheckProcFactory.java:755)
at org.apache.hadoop.hive.ql.lib.DefaultRuleDispatcher.dispatch(DefaultRuleDispatcher.java:89)
at org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.dispatch(DefaultGraphWalker.java:88)
at org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.walk(DefaultGraphWalker.java:128)
at org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.startWalking(DefaultGraphWalker.java:102)
at org.apache.hadoop.hive.ql.parse.TypeCheckProcFactory.genExprNode(TypeCheckProcFactory.java:156)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genExprNodeDesc(SemanticAnalyzer.java:6808)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genHavingPlan(SemanticAnalyzer.java:1323)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genBodyPlan(SemanticAnalyzer.java:5442)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genPlan(SemanticAnalyzer.java:6021)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.analyzeInternal(SemanticAnalyzer.java:6606)
at org.apache.hadoop.hive.ql.parse.BaseSemanticAnalyzer.analyze(BaseSemanticAnalyzer.java:238)
at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:340)
at org.apache.hadoop.hive.ql.Driver.run(Driver.java:736)
at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:210)
at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:287)
at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:517)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.apache.hadoop.util.RunJar.main(RunJar.java:197)