const Type* AggregateFunctionCount::resultTypeForArgumentTypes(
const std::vector<const Type*> &argument_types) const {
if (!canApplyToTypes(argument_types)) {
return nullptr;
}
return &TypeFactory::GetType(kLong);
}
AggregationHandle* AggregateFunctionMin::createHandle(
const std::vector<const Type*> &argument_types) const {
DCHECK(canApplyToTypes(argument_types))
<< "Attempted to create an AggregationHandleMin for argument Type(s) "
<< "that MIN can not be applied to.";
return new AggregationHandleMin(*argument_types.front());
}
const Type* AggregateFunctionMin::resultTypeForArgumentTypes(
const std::vector<const Type*> &argument_types) const {
if (!canApplyToTypes(argument_types)) {
return nullptr;
}
return &(argument_types.front()->getNullableVersion());
}
WindowAggregationHandle* WindowAggregateFunctionCount::createHandle(
const std::vector<const Type*> &argument_types,
const std::vector<std::unique_ptr<const Scalar>> &partition_by_attributes,
const std::vector<std::unique_ptr<const Scalar>> &order_by_attributes,
const bool is_row,
const std::int64_t num_preceding,
const std::int64_t num_following) const {
DCHECK(canApplyToTypes(argument_types))
<< "Attempted to create a WindowAggregationHandleCount for argument Types "
<< "that COUNT can not be applied to (> 1 argument).";
// TODO(Shixuan): Add handle for Count.
return nullptr;
}
AggregationHandle* AggregateFunctionCount::createHandle(
const std::vector<const Type*> &argument_types) const {
DCHECK(canApplyToTypes(argument_types))
<< "Attempted to create an AggregationHandleCount for argument Types "
<< "that COUNT can not be applied to (> 1 argument).";
if (argument_types.empty()) {
// COUNT(*)
return new AggregationHandleCount<true, false>();
} else if (argument_types.front()->isNullable()) {
// COUNT(some_nullable_argument)
return new AggregationHandleCount<false, true>();
} else {
// COUNT(non_nullable_argument)
//
// TODO(chasseur): Modify query optimizer to optimize-away COUNT with a
// non-nullable argument and convert it to COUNT(*).
return new AggregationHandleCount<false, false>();
}
}
