org.apache.ignite.internal.processors.query.stat

Class ColumnStatisticsCollector

java.lang.Object

org.apache.ignite.internal.processors.query.stat.ColumnStatisticsCollector

public class ColumnStatisticsCollector
extends Object

Collector to compute statistic by single column.

Constructor Summary

Constructors

Constructor and Description
ColumnStatisticsCollector(org.gridgain.internal.h2.table.Column col, Comparator<org.gridgain.internal.h2.value.Value> comp) Constructor.
ColumnStatisticsCollector(org.gridgain.internal.h2.table.Column col, Comparator<org.gridgain.internal.h2.value.Value> comp, long ver) Constructor.

Method Summary

Modifier and Type	Method and Description
void	add(org.gridgain.internal.h2.value.Value val) Add value to statistics.
static ColumnStatistics	aggregate(Comparator<org.gridgain.internal.h2.value.Value> comp, List<ColumnStatistics> partStats, StatisticsColumnOverrides overrides) Aggregate specified (partition or local) column statistics into (local or global) single one.
org.gridgain.internal.h2.table.Column	col()
ColumnStatistics	finish() Get total column statistics.

Methods inherited from class java.lang.Object

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

Constructor Detail

ColumnStatisticsCollector

public ColumnStatisticsCollector(org.gridgain.internal.h2.table.Column col,
                                 Comparator<org.gridgain.internal.h2.value.Value> comp)

Constructor.

Parameters:

col - Column to collect statistics by.

comp - Column values comparator.

ColumnStatisticsCollector

public ColumnStatisticsCollector(org.gridgain.internal.h2.table.Column col,
                                 Comparator<org.gridgain.internal.h2.value.Value> comp,
                                 long ver)

Constructor.

Parameters:

col - Column to collect statistics by.

comp - Column values comparator.

ver - Target statistic version.

Method Detail

add

public void add(org.gridgain.internal.h2.value.Value val)

Add value to statistics.

Parameters:

val - Value to add to statistics.

finish

public ColumnStatistics finish()

Get total column statistics.

Returns:

Aggregated column statistics.

col

public org.gridgain.internal.h2.table.Column col()

Returns:

get column.

aggregate

public static ColumnStatistics aggregate(Comparator<org.gridgain.internal.h2.value.Value> comp,
                                         List<ColumnStatistics> partStats,
                                         StatisticsColumnOverrides overrides)

Aggregate specified (partition or local) column statistics into (local or global) single one.

Parameters:

comp - Value comparator.

partStats - Column statistics by partitions.

overrides - Overrides or null to keep calculated values.

Returns:

Column statistics for all partitions.