public class SUM extends AggregateBase<IV> implements INeedsMaterialization
AggregateBase.Annotations
INeedsMaterialization.Requirement
EMPTY_LITERAL, ZERO
DEFAULT_INITIAL_CAPACITY
Constructor and Description |
---|
SUM(boolean distinct,
IValueExpression... expr) |
SUM(BOp[] args,
Map<String,Object> annotations) |
SUM(SUM op) |
Modifier and Type | Method and Description |
---|---|
IV |
done()
Return the final value.
|
IV |
get(IBindingSet bindingSet)
Return the current value of the aggregate (this has a side-effect on the
internal state of the
IAggregate operator). |
INeedsMaterialization.Requirement |
getRequirement()
Note:
SUM only works on numerics. |
void |
reset()
Reset the aggregate's internal state.
|
isDistinct, isWildcard
_clearProperty, _setProperty
__replaceArg, _set, annotations, annotationsCopy, annotationsEqual, annotationsRef, argIterator, args, argsCopy, arity, clearAnnotations, clearProperty, deepCopy, deepCopy, get, getProperty, setArg, setProperty, setUnboundProperty, toArray, toArray
annotationsEqual, annotationsToString, annotationsToString, annotationValueToString, checkArgs, clone, equals, getEvaluationContext, getId, getProperty, getRequiredProperty, hashCode, indent, isController, mutation, shortenName, toShortString, toString, toString
finalize, getClass, notify, notifyAll, wait, wait, wait
toString
annotations, argIterator, args, arity, clone, get, getEvaluationContext, getId, getProperty, getRequiredProperty, isController, setProperty, toArray, toArray, toShortString, toString
getProperty
public SUM(SUM op)
public SUM(boolean distinct, IValueExpression... expr)
public void reset()
IAggregate
reset
in interface IAggregate<IV>
public IV done()
IAggregate
done
in interface IAggregate<IV>
public IV get(IBindingSet bindingSet)
AggregateBase
IAggregate
operator). Functions which can
not produce an intermediate result, such as AVERAGE, MAY return
null
.
Note: If evaluation of the IAggregate
throws an error, then that
error must be "sticky" and reported out by IAggregate.done()
as well. This
contract is relied on to correctly propagate errors within a group when
using incremental (pipelined) evaluation of IAggregate
s. The
error state is cleared by IAggregate.reset()
.
Operation is not implemented by this class and must be overridden if the
AggregateBase
is to be directly evaluated. However, note that the
computation of aggregate functions is often based on hard coded
recognition of the appropriate function code.
Note: DISTINCT is merely carried as a marker on COUNT (and the other
aggregate functions). The application of DISTINCT to the inner expression
to form a column projection is handled by the driving evaluation logic
rather than by AggregateBase.get(IBindingSet)
.
get
in interface IAggregate<IV>
get
in interface IValueExpression<IV>
get
in class AggregateBase<IV>
bindingSet
- The binding set.public INeedsMaterialization.Requirement getRequirement()
SUM
only works on numerics. If they are inline, then that
is great. Otherwise it will handle a materialized numeric literal and do
type promotion, which always results in a signed inline number IV and
then operate on that.getRequirement
in interface INeedsMaterialization
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