org.apache.hadoop.hive.ql.optimizer.calcite.rules

Class HiveRewriteToDataSketchesRules

java.lang.Object

org.apache.hadoop.hive.ql.optimizer.calcite.rules.HiveRewriteToDataSketchesRules

public final class HiveRewriteToDataSketchesRules
extends Object

This rule could rewrite aggregate calls to be calculated using sketch based functions.
Currently it can rewrite:

• count(distinct(x)) using CountDistinctRewrite
• percentile_disc(0.2) within group (order by id) using PercentileDiscRewrite
• cume_dist() over (order by id) using CumeDistRewrite

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	HiveRewriteToDataSketchesRules.AbstractRankBasedRewriteRule Provides a generic way to rewrite function into using an estimation based on CDF.
static class	HiveRewriteToDataSketchesRules.CountDistinctRewrite Rewrites count(distinct(x)) to distinct counting sketches.
static class	HiveRewriteToDataSketchesRules.CumeDistRewriteRule Rewrites cume_dist() over (order by id).
static class	HiveRewriteToDataSketchesRules.NTileRewrite Rewrites ntile(n) over (order by id).
static class	HiveRewriteToDataSketchesRules.PercentileDiscRewrite Rewrites percentile_disc(0.2) within group (order by id).
static class	HiveRewriteToDataSketchesRules.RankRewriteRule Rewrites rank() over (order by id).

Field Summary

Fields

Modifier and Type	Field and Description
protected static org.slf4j.Logger	LOG

Constructor Summary

Constructors

Constructor and Description
HiveRewriteToDataSketchesRules()

Method Summary

Methods inherited from class java.lang.Object

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

Field Detail

LOG

protected static final org.slf4j.Logger LOG

Constructor Detail

HiveRewriteToDataSketchesRules

public HiveRewriteToDataSketchesRules()