[HIVE-2736] Hive UDFs cannot emit binary constants

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 0.9.0
• Fix Version/s: 0.10.0
• Component/s: Query Processor, Serializers/Deserializers, UDF
• Labels: newbie
• Assignee: Philip Tromans
• Reporter: Philip Tromans
• Created: 23/Jan/12 14:22
• Updated: 10/Jan/13 19:53
• Resolved: 07/Jun/12 14:56

Description

I recently wrote a UDF which emits BINARY values (as implemented in HIVE-2380). When testing this, I encountered the following exception (because I was evaluating f(g(constant string))) and g() was emitting a BytesWritable type.

FAILED: Hive Internal Error: java.lang.RuntimeException(Internal error: Cannot find ConstantObjectInspector for BINARY)
java.lang.RuntimeException: Internal error: Cannot find ConstantObjectInspector for BINARY
at org.apache.hadoop.hive.serde2.objectinspector.primitive.PrimitiveObjectInspectorFactory.getPrimitiveWritableConstantObjectInspector(PrimitiveObjectInspectorFactory.java:196)
at org.apache.hadoop.hive.serde2.objectinspector.ObjectInspectorUtils.getConstantObjectInspector(ObjectInspectorUtils.java:899)
at org.apache.hadoop.hive.ql.udf.generic.GenericUDF.initializeAndFoldConstants(GenericUDF.java:128)
at org.apache.hadoop.hive.ql.plan.ExprNodeGenericFuncDesc.newInstance(ExprNodeGenericFuncDesc.java:214)
at org.apache.hadoop.hive.ql.parse.TypeCheckProcFactory$DefaultExprProcessor.getXpathOrFuncExprNodeDesc(TypeCheckProcFactory.java:684)
at org.apache.hadoop.hive.ql.parse.TypeCheckProcFactory$DefaultExprProcessor.process(TypeCheckProcFactory.java:805)
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:125)
at org.apache.hadoop.hive.ql.lib.DefaultGraphWalker.startWalking(DefaultGraphWalker.java:102)
at org.apache.hadoop.hive.ql.parse.TypeCheckProcFactory.genExprNode(TypeCheckProcFactory.java:161)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genExprNodeDesc(SemanticAnalyzer.java:7708)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genSelectPlan(SemanticAnalyzer.java:2301)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genSelectPlan(SemanticAnalyzer.java:2103)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genPostGroupByBodyPlan(SemanticAnalyzer.java:6126)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genBodyPlan(SemanticAnalyzer.java:6097)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.genPlan(SemanticAnalyzer.java:6723)
at org.apache.hadoop.hive.ql.parse.SemanticAnalyzer.analyzeInternal(SemanticAnalyzer.java:7484)
at org.apache.hadoop.hive.ql.parse.BaseSemanticAnalyzer.analyze(BaseSemanticAnalyzer.java:243)
at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:430)
at org.apache.hadoop.hive.ql.Driver.compile(Driver.java:337)
at org.apache.hadoop.hive.ql.Driver.run(Driver.java:889)
at org.apache.hadoop.hive.cli.CliDriver.processLocalCmd(CliDriver.java:255)
at org.apache.hadoop.hive.cli.CliDriver.processCmd(CliDriver.java:212)
at org.apache.hadoop.hive.cli.CliDriver.processLine(CliDriver.java:403)
at org.apache.hadoop.hive.cli.CliDriver.run(CliDriver.java:671)
at org.apache.hadoop.hive.cli.CliDriver.main(CliDriver.java:554)
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)

It looks like a pretty simple fix - add a case for BINARY in PrimitiveObjectInspectorFactory.getPrimitiveWritableConstantObjectInspector() and implement a WritableConstantByteArrayObjectInspector class (almost identical to the others). I'm happy to do this, although this is my first foray into the world of contributing to FOSS so I might end up asking a few stupid questions.