GridGain™ 4.3.1e
Enterprise "Big Data" Edition

Interface GridCacheFieldsQueryFuture

All Superinterfaces:
Callable<Collection<List<Object>>>, GridCacheQueryFuture<List<Object>>, GridFuture<Collection<List<Object>>>, GridIterable<List<Object>>, GridIterator<List<Object>>, GridSerializableIterator<List<Object>>, Iterable<List<Object>>, Iterator<List<Object>>, Serializable

public interface GridCacheFieldsQueryFuture
extends GridCacheQueryFuture<List<Object>>

Cache query future returned by GridCacheFieldsQuery.execute(GridProjection...) method. Note that this future is different from GridCacheQueryFuture only with addition of GridCacheFieldsQueryFuture.metadata() method which provides field descriptors for all returned fields.

Please refer to GridCacheFieldsQuery javadoc documentation for more information.

See Also:

Method Summary
 GridFuture<List<GridCacheQueryFieldDescriptor>> metadata()
          Gets future for received result metadata.
Methods inherited from interface org.gridgain.grid.cache.query.GridCacheQueryFuture
available, cancel, isDone, size
Methods inherited from interface org.gridgain.grid.GridFuture
concurrentNotify, concurrentNotify, duration, get, get, get, isCancelled, listenAsync, predicate, startTime, stopListenAsync, syncNotify, syncNotify
Methods inherited from interface java.util.concurrent.Callable
Methods inherited from interface org.gridgain.grid.lang.GridIterable
Methods inherited from interface org.gridgain.grid.lang.GridIterator
hasNextX, nextX, removeX
Methods inherited from interface java.util.Iterator
hasNext, next, remove

Method Detail


GridFuture<List<GridCacheQueryFieldDescriptor>> metadata()
Gets future for received result metadata. Metadata describes fields included in result set, describing their names, types, etc.

If GridCacheFieldsQuery.includeMetadata() flag is true, future is blocked until first result page is received. Otherwise, future is initially in done state and returns null.

Note that even if GridCacheFieldsQuery.includeMetadata() flag is true, you can also get null metadata. This happens when your query failed locally on each node with table not found error. If you request only one data type, check it's name. Otherwise, this can mean that your query is invalid or that there is no data you requested, depending on how is data is collocated in cache.

Meta data.

GridGain™ 4.3.1e
Enterprise "Big Data" Edition

GridGain - In-Memory Big Data
Enterprise "Big Data" Edition, ver. 4.3.1e.10112012
2012 Copyright © GridGain Systems
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