Package 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
    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 Details

    • 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.