public class SelectivityHistogram<T extends Comparable<? super T>> extends Object
Modifier and Type | Field and Description |
---|---|
static double |
BUCKET_USAGE_GUESS
A guess about how much of a bucket is in use when there is some overlap.
|
Constructor and Description |
---|
SelectivityHistogram() |
Modifier and Type | Method and Description |
---|---|
void |
addHistogramBounds(List<T> bounds,
List<? extends Number> counts) |
void |
addHistogramExact(Map<T,? extends Number> histogram) |
boolean |
isValid()
A histogram is not valid until either addHistogramBounds() or addHistogramExact() is called.
|
SelectivityHistogram<T> |
join(SelectivityHistogram<T> other)
Get a new histogram that represents the join of this histogram with another.
|
long |
size()
Get the number of rows represented by this histogram.
|
String |
toString() |
public static final double BUCKET_USAGE_GUESS
public long size()
public boolean isValid()
public SelectivityHistogram<T> join(SelectivityHistogram<T> other)
Copyright © 2020 University of California, Santa Cruz. All rights reserved.