com.hazelcast.map.impl.query

Interface PartitionScanExecutor

All Known Implementing Classes:

CallerRunsPartitionScanExecutor, ParallelPartitionScanExecutor

public interface PartitionScanExecutor

Responsible for executing a full partition scan for the given partitions. May execute the scan in the calling thread or delegate to other thread - it depends on the implementation.

Method Summary

Modifier and Type	Method and Description
void	execute(String mapName, Predicate predicate, Collection<Integer> partitions, Result result)
QueryableEntriesSegment	execute(String mapName, Predicate predicate, int partitionId, int tableIndex, int fetchSize) Executes the predicate on a partition chunk.

Method Detail

execute

void execute(String mapName,
             Predicate predicate,
             Collection<Integer> partitions,
             Result result)

execute

QueryableEntriesSegment execute(String mapName,
                                Predicate predicate,
                                int partitionId,
                                int tableIndex,
                                int fetchSize)

Executes the predicate on a partition chunk. The offset in the partition is defined by the tableIndex and the soft limit is defined by the fetchSize. The method returns the matched entries and an index from which new entries can be fetched which allows for efficient iteration of query results.

NOTE Iterating the query results using the returned next table index should be done only when the IMap is not being mutated and the cluster is stable (there are no migrations or membership changes). In other cases, entries are rearranged and the you may get the same query result twice or may miss some query results that match the predicate.

Parameters:

mapName - the map name

predicate - the predicate which the entries must match

partitionId - the partition which is queried

tableIndex - the index from which entries are queried

fetchSize - the soft limit for the number of entries to fetch

Returns:

entries matching the predicate and a table index from which new entries can be fetched