com.hazelcast.query

Interface LocalIndexStats

All Superinterfaces:

com.hazelcast.instance.LocalInstanceStats

public interface LocalIndexStats
extends com.hazelcast.instance.LocalInstanceStats

Provides local statistics for an index to be used by MemberState implementations.

Method Summary

Modifier and Type	Method and Description
long	getAverageHitLatency() Returns the average hit latency (in nanoseconds) for the index.
double	getAverageHitSelectivity() Returns the average selectivity of the hits served by the index.
long	getHitCount() Returns the total number of hits into the index.
long	getInsertCount() Returns the number of insert operations performed on the index.
long	getMemoryCost() Returns the memory cost of the index in bytes.
long	getQueryCount() Returns the total number of queries served by the index.
long	getRemoveCount() Returns the number of remove operations performed on the index.
long	getTotalInsertLatency() Returns the total latency (in nanoseconds) of insert operations performed on the index.
long	getTotalRemoveLatency() Returns the total latency (in nanoseconds) of remove operations performed on the index.
long	getTotalUpdateLatency() Returns the total latency (in nanoseconds) of update operations performed on the index.
long	getUpdateCount() Returns the number of update operations performed on the index.

Methods inherited from interface com.hazelcast.instance.LocalInstanceStats

getCreationTime

Method Detail

getQueryCount

long getQueryCount()

Returns the total number of queries served by the index.

To calculate the index hit rate just divide the returned value by a value returned by LocalMapStats.getQueryCount().

The returned value may be less than the one returned by getHitCount() since a single query may hit the same index more than once.

getHitCount

long getHitCount()

Returns the total number of hits into the index.

The returned value may be greater than the one returned by getQueryCount() since a single query may hit the same index more than once.

getAverageHitLatency

long getAverageHitLatency()

Returns the average hit latency (in nanoseconds) for the index.

getAverageHitSelectivity

double getAverageHitSelectivity()

Returns the average selectivity of the hits served by the index.

The returned value is in the range from 0.0 to 1.0. Values close to 1.0 indicate a high selectivity meaning the index is efficient; values close to 0.0 indicate a low selectivity meaning the index efficiency is approaching an efficiency of a simple full scan.

getInsertCount

long getInsertCount()

Returns the number of insert operations performed on the index.

getTotalInsertLatency

long getTotalInsertLatency()

Returns the total latency (in nanoseconds) of insert operations performed on the index.

To compute the average latency divide the returned value by insert operation count.

getUpdateCount

long getUpdateCount()

Returns the number of update operations performed on the index.

getTotalUpdateLatency

long getTotalUpdateLatency()

Returns the total latency (in nanoseconds) of update operations performed on the index.

To compute the average latency divide the returned value by update operation count.

getRemoveCount

long getRemoveCount()

Returns the number of remove operations performed on the index.

getTotalRemoveLatency

long getTotalRemoveLatency()

Returns the total latency (in nanoseconds) of remove operations performed on the index.

To compute the average latency divide the returned value by remove operation count.

getMemoryCost

long getMemoryCost()

Returns the memory cost of the index in bytes.

Currently, for on-heap indexes (OBJECT and BINARY storages), the returned value is just a best-effort approximation and doesn't indicate a precise on-heap memory usage of the index.