com.yahoo.bard.webservice.data.config.metric.makers

Class AggregationAverageMaker

java.lang.Object

com.yahoo.bard.webservice.data.config.metric.makers.MetricMaker

com.yahoo.bard.webservice.data.config.metric.makers.AggregationAverageMaker

public class AggregationAverageMaker
extends MetricMaker

Makes a LogicalMetric that wraps existing metrics and average them across a coarser time grain.

The constructed metric takes aggregated data from a finer time grain (i.e. DefaultTimeGrain.DAY) and computes an average across a coarser time grain (i.e. DefaultTimeGrain.WEEK). For example, given the total number of visitors to www.example.com for each day of the week, we can compute the average number of daily visitors to example.com for the entire week.

A nested average requires the following columns:

• an inner query constant one
• an inner query numeric aggregation or post aggregation field to sum
• and outer query sum of the constant which provide a row count
• an outer query sum of the inner numeric summand
• finally, a post aggregation in the outer query dividing the sum by the count

Field Summary

Fields

Modifier and Type	Field and Description
static PostAggregation	COUNT_FIELD_OUTER
static PostAggregation	COUNT_INNER
static Aggregation	COUNT_OUTER

Fields inherited from class com.yahoo.bard.webservice.data.config.metric.makers.MetricMaker

metrics, NO_OP_MAP_PROVIDER, NO_OP_MAPPER

Constructor Summary

Constructors

Constructor and Description
AggregationAverageMaker(MetricDictionary metrics, ZonelessTimeGrain innerGrain) Constructor.

Method Summary

Modifier and Type	Method and Description
protected int	getDependentMetricsRequired() Get the number of dependent metrics the maker requires for making the metric.
protected LogicalMetric	makeInner(LogicalMetricInfo logicalMetricInfo, List<String> dependentMetrics) Delegated to for actually making the metric.

Methods inherited from class com.yahoo.bard.webservice.data.config.metric.makers.MetricMaker

assertDependentMetricsExist, assertRequiredDependentMetricCount, getDependentQuery, getMergedQuery, getNumericField, getNumericField, getSketchField, getSketchField, make, make, make, makeInner

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

COUNT_INNER

public static final PostAggregation COUNT_INNER

COUNT_OUTER

@NotNull
public static final Aggregation COUNT_OUTER

COUNT_FIELD_OUTER

public static final PostAggregation COUNT_FIELD_OUTER

Constructor Detail

AggregationAverageMaker

public AggregationAverageMaker(MetricDictionary metrics,
                               ZonelessTimeGrain innerGrain)

Constructor.

Parameters:

metrics - A mapping of metric names to the corresponding LogicalMetrics. Used to resolve metric names when making the logical metric.

innerGrain - The time grain across which queries should aggregate.

Method Detail

makeInner

protected LogicalMetric makeInner(LogicalMetricInfo logicalMetricInfo,
                                  List<String> dependentMetrics)

Description copied from class: MetricMaker

Delegated to for actually making the metric.

Overrides:

makeInner in class MetricMaker

Parameters:

logicalMetricInfo - Logical metric info provider

dependentMetrics - Metrics this metric depends on

Returns:

the new logicalMetric

getDependentMetricsRequired

protected int getDependentMetricsRequired()

Description copied from class: MetricMaker

Get the number of dependent metrics the maker requires for making the metric.

Specified by:

getDependentMetricsRequired in class MetricMaker

Returns:

the number of dependent metrics the maker requires for making the metric