com.apple.foundationdb.record.provider.foundationdb.cursors

Class SizeStatisticsCollectorCursor.SizeStatisticsResults

java.lang.Object

com.apple.foundationdb.record.provider.foundationdb.cursors.SizeStatisticsCollectorCursor.SizeStatisticsResults

Enclosing class:

SizeStatisticsCollectorCursor

public static class SizeStatisticsCollectorCursor.SizeStatisticsResults
extends Object

Encapsulates the distribution statistics returned by a SizeStatisticsCollectorCursor.

Method Summary

Modifier and Type	Method and Description
double	getAverage() Get the mean size (in bytes) of combined key-value pairs in the requested key range.
double	getAverageKeySize() Get the mean size (in bytes) of keys in the requested key range.
double	getAverageValueSize() Get the mean size (in bytes) of values in the requested key range.
long	getKeyCount() Get the total number of keys in the requested key range.
long	getKeySize() Get the total size (in bytes) of all keys in the requested key range.
long	getMaxKeySize() Get the size (in bytes) of the largest key in the requested key range.
long	getMaxValueSize() Get the size (in bytes) of the largest value in the requested key range.
double	getMedian() Get an estimate for the size of the median key-value pair.
double	getP90() Get an estimate for the size of the 90th percentile key-value pair.
double	getP95() Get an estimate for the size of the 95th percentile key-value pair.
double	getProportion(double proportion) Get an estimate for the size for which the provided proportion of key-value pairs have a combined size that is less than that size.
long[]	getSizeBuckets() Get an array of buckets used to get an estimate of size distribution.
long	getTotalSize() Get the total size (in bytes) of all keys and values in the requested key range.
long	getValueSize() Get the total size (in bytes) of all values in the requested key range.

Methods inherited from class java.lang.Object

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

Method Detail

getKeyCount

@Nonnull
public long getKeyCount()

Get the total number of keys in the requested key range.

Returns:

keyCount the total number of keys in the requested key range.

getKeySize

@Nonnull
public long getKeySize()

Get the total size (in bytes) of all keys in the requested key range.

Returns:

the size (in bytes) of the requested keys

getMaxKeySize

@Nonnull
public long getMaxKeySize()

Get the size (in bytes) of the largest key in the requested key range.

Returns:

the size (in bytes) of the largest key

getValueSize

@Nonnull
public long getValueSize()

Get the total size (in bytes) of all values in the requested key range.

Returns:

the size (in bytes) of the requested values

getMaxValueSize

@Nonnull
public long getMaxValueSize()

Get the size (in bytes) of the largest value in the requested key range.

Returns:

the size (in bytes) of the largest value

getTotalSize

@Nonnull
public long getTotalSize()

Get the total size (in bytes) of all keys and values in the requested key range.

Returns:

the size (in bytes) of the requested keys and values

getAverageKeySize

@Nonnull
public double getAverageKeySize()

Get the mean size (in bytes) of keys in the requested key range.

Returns:

the mean size (in bytes) of all keys

getAverageValueSize

@Nonnull
public double getAverageValueSize()

Get the mean size (in bytes) of values in the requested key range.

Returns:

the mean size (in bytes) of all values

getAverage

@Nonnull
public double getAverage()

Get the mean size (in bytes) of combined key-value pairs in the requested key range.

Returns:

the mean size (in bytes) of all key-value pairs

getSizeBuckets

@Nonnull
public long[] getSizeBuckets()

Get an array of buckets used to get an estimate of size distribution. Each bucket i contains the number of key-value pairs whose combined size is between greater than or equal to 2ⁱ and less than 2^{i + 1}. In other words, bucket i contains the number of key-value pairs where the combined size's most significant bit was bit i (numbering from the least significant bit and indexing from zero).

Returns:

an array with a distribution of the sizes of key-value pairs

getProportion

public double getProportion(double proportion)

Get an estimate for the size for which the provided proportion of key-value pairs have a combined size that is less than that size. For example, if 0.8 is passed as the proportion, then this gives an estimate for the 80th percentile value. This value is inexact as it must be interpolated from the recorded size distribution.

Parameters:

proportion - the proportion of key-value pairs that should have a size less than the returned size

Returns:

an estimate for the size that is consistent with the given proportion

getMedian

public double getMedian()

Get an estimate for the size of the median key-value pair.

Returns:

an estimate for the median key-value pair

getP90

public double getP90()

Get an estimate for the size of the 90th percentile key-value pair.

Returns:

an estimate for the size of the 90th percentile key-value pair

getP95

public double getP95()

Get an estimate for the size of the 95th percentile key-value pair.

Returns:

an estimate for the size of the 95th percentile key-value pair