@Internal public final class TemporalTableFunctionImpl extends TemporalTableFunction
timeAttribute, for which it returns matching version of the
underlyingHistoryTable, from which this
This function shouldn't be evaluated. Instead calls to it should be rewritten by the optimiser into other operators (like Temporal Table Join).
|Modifier and Type||Method and Description|
Returns the result type of the evaluation method.
Returns the logic for performing type inference of a call to this function definition.
collect, getKind, getParameterTypes, setCollector
close, functionIdentifier, open, toString
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
public void eval(Timestamp t)
public Expression getTimeAttribute()
public Expression getPrimaryKey()
public TypeInference getTypeInference(DataTypeFactory typeFactory)
The type inference process is responsible for inferring unknown types of input arguments, validating input arguments, and producing result types. The type inference process happens independent of a function body. The output of the type inference is used to search for a corresponding runtime implementation.
Instances of type inference can be created by using
BuiltInFunctionDefinitions for concrete usage examples.
The type inference for user-defined functions is automatically extracted using reflection. It
does this by analyzing implementation methods such as
eval() or accumulate() and the generic
parameters of a function class if present. If the reflective information is not sufficient, it can
be supported and enriched with
Note: Overriding this method is only recommended for advanced users. If a custom type inference is specified, it is the responsibility of the implementer to make sure that the output of the type inference process matches with the implementation method:
The implementation method must comply with each
by the type inference. For example, if
is an expected argument type, the method must accept a call
Regular Java calling semantics (including type widening and autoboxing) are applied when calling
an implementation method which means that the signature can be
The runtime will take care of converting the data to the data format specified by the
DataType.getConversionClass() coming from the type inference logic.
public RowTypeInfo getResultType()
public QueryOperation getUnderlyingHistoryTable()
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