public class CountAggFunction extends DeclarativeAggregateFunction
Constructor and Description |
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CountAggFunction() |
Modifier and Type | Method and Description |
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Expression[] |
accumulateExpressions()
Expressions for accumulating the mutable aggregation buffer based on an input row.
|
UnresolvedReferenceExpression[] |
aggBufferAttributes()
All fields of the aggregate buffer.
|
DataType[] |
getAggBufferTypes()
All types of the aggregate buffer.
|
DataType |
getResultType()
The result type of the function.
|
Expression |
getValueExpression()
An expression which returns the final value for this aggregate function.
|
Expression[] |
initialValuesExpressions()
Expressions for initializing empty aggregation buffers.
|
Expression[] |
mergeExpressions()
A sequence of expressions for merging two aggregation buffers together.
|
int |
operandCount()
How many operands your function will deal with.
|
Expression[] |
retractExpressions()
Expressions for retracting the mutable aggregation buffer based on an input row.
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getKind, getTypeInference, mergeOperand, mergeOperands, operand, operands
close, functionIdentifier, open, toString
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
getRequirements, isDeterministic, supportsConstantFolding
public int operandCount()
DeclarativeAggregateFunction
operandCount
in class DeclarativeAggregateFunction
public UnresolvedReferenceExpression[] aggBufferAttributes()
DeclarativeAggregateFunction
aggBufferAttributes
in class DeclarativeAggregateFunction
public DataType[] getAggBufferTypes()
DeclarativeAggregateFunction
getAggBufferTypes
in class DeclarativeAggregateFunction
public DataType getResultType()
DeclarativeAggregateFunction
getResultType
in class DeclarativeAggregateFunction
public Expression[] initialValuesExpressions()
DeclarativeAggregateFunction
initialValuesExpressions
in class DeclarativeAggregateFunction
public Expression[] accumulateExpressions()
DeclarativeAggregateFunction
accumulateExpressions
in class DeclarativeAggregateFunction
public Expression[] retractExpressions()
DeclarativeAggregateFunction
retractExpressions
in class DeclarativeAggregateFunction
public Expression[] mergeExpressions()
DeclarativeAggregateFunction
attributeName
and mergeOperand(attributeName)
to refer to the attributes corresponding to each of the buffers
being merged.mergeExpressions
in class DeclarativeAggregateFunction
public Expression getValueExpression()
DeclarativeAggregateFunction
getValueExpression
in class DeclarativeAggregateFunction
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