func CanBuildDefaultSelectExecutionPlan(lp *LogicalPlan, reg udf.FunctionRegistry) bool {
	return !lp.GroupingStmt
}
CanBuildDefaultSelectExecutionPlan checks whether the given statement
allows to use an defaultSelectExecutionPlan.
package execution
import (
	"fmt"
	"gopkg.in/sensorbee/sensorbee.v0/bql/udf"
	"gopkg.in/sensorbee/sensorbee.v0/core"
	"gopkg.in/sensorbee/sensorbee.v0/data"
)
type defaultSelectExecutionPlan struct {
	streamRelationStreamExecutionPlan
}