Details
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Bug
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Status: Closed
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Major
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Resolution: Won't Fix
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None
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None
Description
If explicitly return a CompositeType in udf.getResultType, will result in some failures in chained operators.
For example: consider a simple UDF,
object Func extends ScalarFunction { def eval(row: Row): Row = { row } override def getParameterTypes(signature: Array[Class[_]]): Array[TypeInformation[_]] = Array(Types.ROW(Types.INT)) override def getResultType(signature: Array[Class[_]]): TypeInformation[_] = Types.ROW(Types.INT) }
This should work perfectly since it's just a simple pass through, however
@Test def testRowType(): Unit = { val data = List( Row.of(Row.of(12.asInstanceOf[Integer]), "1") ) val env = StreamExecutionEnvironment.getExecutionEnvironment val stream = env.fromCollection(data)(Types.ROW(Types.ROW(Types.INT), Types.STRING)) val tEnv = TableEnvironment.getTableEnvironment(env) val table = stream.toTable(tEnv, 'a, 'b) tEnv.registerFunction("func", Func) tEnv.registerTable("t", table) // This works perfectly val result1 = tEnv.sqlQuery("SELECT func(a) FROM t").toAppendStream[Row] result1.addSink(new StreamITCase.StringSink[Row]) // This throws exception val result2 = tEnv.sqlQuery("SELECT func(a) as myRow FROM t").toAppendStream[Row] result2.addSink(new StreamITCase.StringSink[Row]) env.execute() }
Exception code:
java.lang.IndexOutOfBoundsException: index (1) must be less than size (1) at com.google.common.base.Preconditions.checkElementIndex(Preconditions.java:310) at com.google.common.base.Preconditions.checkElementIndex(Preconditions.java:293) at com.google.common.collect.SingletonImmutableList.get(SingletonImmutableList.java:41) at org.apache.calcite.sql.type.InferTypes$2.inferOperandTypes(InferTypes.java:83) at org.apache.calcite.sql.validate.SqlValidatorImpl.inferUnknownTypes(SqlValidatorImpl.java:1777) at org.apache.calcite.sql.validate.SqlValidatorImpl.expandSelectItem(SqlValidatorImpl.java:459) at org.apache.calcite.sql.validate.SqlValidatorImpl.expandStar(SqlValidatorImpl.java:349) ...
This is due to the fact that Calcite inferOperandTypes does not expect to infer a struct RelDataType.
Attachments
Issue Links
- is blocked by
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FLINK-11006 Update Calcite dependency to 1.18
- Closed
- is related to
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CALCITE-2468 Validator throws IndexOutOfBoundsException when trying to infer operand type from struct return type
- Closed
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FLINK-9484 Improve generic type inference for User-Defined Functions
- Resolved
- links to
Dug a little deeper in Calcite and found that in:
https://github.com/apache/calcite/blob/master/core/src/main/java/org/apache/calcite/sql/type/InferTypes.java#L68
Seems like if the return type is inferred as a record, or .isStruct() == true, "it must have the same number of fields as the number of operands." which clearly is not the case here since the following expression: AS(func(a), "myRow") only passes over the func(a) for type inference, but not the alias "myRow"