com.hazelcast.map.impl.query

Interface MapQueryEngine

All Known Implementing Classes:

MapQueryEngineImpl

public interface MapQueryEngine

Responsible for executing queries on the IMap.

Method Summary

Methods

Modifier and Type	Method and Description
QueryResult	invokeQueryAllPartitions(String mapName, Predicate predicate, IterationType iterationType) Queries all partitions.
QueryResult	invokeQueryLocalPartitions(String mapName, Predicate predicate, IterationType iterationType) Query all local partitions.
Set	queryAllPartitionsWithPagingPredicate(String mapName, PagingPredicate pagingPredicate, IterationType iterationType) Queries all partitions with a paging predicate.
QueryResult	queryLocalPartition(String mapName, Predicate predicate, int partitionId, IterationType iterationType) Executes a query on a specific local partition.
QueryResult	queryLocalPartitions(String mapName, Predicate predicate, IterationType iterationType) Executes a query on all the local partitions.
Set	queryLocalPartitionsWithPagingPredicate(String mapName, PagingPredicate pagingPredicate, IterationType iterationType) Query all local partitions with a paging predicate.

Method Detail

queryLocalPartitions

QueryResult queryLocalPartitions(String mapName,
                               Predicate predicate,
                               IterationType iterationType)
                                 throws ExecutionException,
                                        InterruptedException

Executes a query on all the local partitions.

- Uses Indexes - Accepts PagingPredicate - Query executed in the calling thread - predicate evaluation will be parallelized if QUERY_PREDICATE_PARALLEL_EVALUATION is enabled or a PagingPredicate is used. - may return empty QueryResult (with a properly initialized result limit size) if query is executed during migrations and migration conditions do not allow for safe retrieval of results (ie. there are migrations in flight or partition state version is different at the end of query vs the version observed at the beginning of query). In this case, partitionIds are not set on the QueryResult, so callers will ignore these results and fallback to QueryPartitionOperations.

Parameters:

mapName - the name of the map

predicate - the predicate

Returns:

the QueryResult

Throws:

ExecutionException

InterruptedException

queryLocalPartition

QueryResult queryLocalPartition(String mapName,
                              Predicate predicate,
                              int partitionId,
                              IterationType iterationType)

Executes a query on a specific local partition.

- Does NOT use Indexes - Accepts PagingPredicate - Sequential full table scan - Query executed in the calling thread

todo: what happens when the partition is not local?

Parameters:

mapName - map name.

predicate - any predicate.

partitionId - partition id.

Returns:

result of query

invokeQueryLocalPartitions

QueryResult invokeQueryLocalPartitions(String mapName,
                                     Predicate predicate,
                                     IterationType iterationType)

Query all local partitions.

- Does NOT accept PagingPredicate - Query executed in an Operation on this member (NOT in the calling thread) - Calls queryLocalPartitions(String, Predicate, IterationType) in an operation

Parameters:

mapName - map name.

predicate - except paging predicate.

iterationType - the IterationType

invokeQueryAllPartitions

QueryResult invokeQueryAllPartitions(String mapName,
                                   Predicate predicate,
                                   IterationType iterationType)

Queries all partitions. Paging predicates are not allowed. - Does NOT accept PagingPredicate - Query executed in an Operation on each member (NOT in the calling thread) - Calls queryLocalPartitions(String, Predicate, IterationType) in an operation

Parameters:

mapName - map name.

predicate - except paging predicate.

iterationType - the IterationType

queryLocalPartitionsWithPagingPredicate

Set queryLocalPartitionsWithPagingPredicate(String mapName,
                                          PagingPredicate pagingPredicate,
                                          IterationType iterationType)

Query all local partitions with a paging predicate.

- Query executed in an Operation on this member (or other members if some partitions are not local)

TODO: it would be better to have a single queryLocal... method and let the implementation figure out how to deal with a regular predicate and a paging predicate. No need to have that in the interface. The problem is that currently the signatures don't match up. This implementation detail should not be exposed through the interface.

Parameters:

mapName - map name.

pagingPredicate - to queryOnMembers.

iterationType - type of IterationType

Returns:

SortedQueryResultSet

queryAllPartitionsWithPagingPredicate

Set queryAllPartitionsWithPagingPredicate(String mapName,
                                        PagingPredicate pagingPredicate,
                                        IterationType iterationType)

Queries all partitions with a paging predicate.

- Query executed in an Operation on each member (NOT in the calling thread)

TODO: it would be better to have single queryAll method and let the implementation figure out how to deal with a paging predicate. See comment in queryLocalPartitionsWithPagingPredicate(java.lang.String, com.hazelcast.query.PagingPredicate, com.hazelcast.util.IterationType)

Parameters:

mapName - map name.

pagingPredicate - to queryOnMembers.

iterationType - type of IterationType

Returns:

SortedQueryResultSet