org.apache.cassandra.db.partitions

Interface Partition

All Known Subinterfaces:

CachedPartition

All Known Implementing Classes:

AbstractBTreePartition, AtomicBTreePartition, CachedBTreePartition, FilteredPartition, ImmutableBTreePartition, PartitionUpdate

public interface Partition

In-memory representation of a Partition. Note that most of the storage engine works through iterators (UnfilteredPartitionIterator) to avoid "materializing" a full partition/query response in memory as much as possible, and so Partition objects should be use as sparingly as possible. There is a couple of cases where we do need to represent partition in-memory (memtables and row cache).

Method Summary

Modifier and Type	Method and Description
PartitionColumns	columns()
Row	getRow(Clustering clustering) Returns the row corresponding to the provided clustering, or null if there is not such row.
boolean	isEmpty() Whether the partition object has no informations at all, including any deletion informations.
CFMetaData	metadata()
DecoratedKey	partitionKey()
DeletionTime	partitionLevelDeletion()
SearchIterator<Clustering,Row>	searchIterator(ColumnFilter columns, boolean reversed) Returns an iterator that allows to search specific rows efficiently.
EncodingStats	stats()
UnfilteredRowIterator	unfilteredIterator() Returns an UnfilteredRowIterator over all the rows/RT contained by this partition.
UnfilteredRowIterator	unfilteredIterator(ColumnFilter columns, Slices slices, boolean reversed) Returns an UnfilteredRowIterator over the rows/RT contained by this partition selected by the provided slices.

Method Detail

metadata

CFMetaData metadata()

partitionKey

DecoratedKey partitionKey()

partitionLevelDeletion

DeletionTime partitionLevelDeletion()

columns

PartitionColumns columns()

stats

EncodingStats stats()

isEmpty

boolean isEmpty()

Whether the partition object has no informations at all, including any deletion informations.

getRow

Row getRow(Clustering clustering)

Returns the row corresponding to the provided clustering, or null if there is not such row.

searchIterator

SearchIterator<Clustering,Row> searchIterator(ColumnFilter columns,
                                              boolean reversed)

Returns an iterator that allows to search specific rows efficiently.

unfilteredIterator

UnfilteredRowIterator unfilteredIterator()

Returns an UnfilteredRowIterator over all the rows/RT contained by this partition.

unfilteredIterator

UnfilteredRowIterator unfilteredIterator(ColumnFilter columns,
                                         Slices slices,
                                         boolean reversed)

Returns an UnfilteredRowIterator over the rows/RT contained by this partition selected by the provided slices.