Package 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 Details

    • metadata

      TableMetadata metadata()

    • partitionKey

      DecoratedKey partitionKey()

    • partitionLevelDeletion

      DeletionTime partitionLevelDeletion()

    • columns

      RegularAndStaticColumns columns()

    • stats

      EncodingStats stats()

    • isEmpty

      boolean isEmpty()
      Whether the partition object has no informations at all, including any deletion informations.

    • hasRows

      boolean hasRows()
      Whether the partition object has rows. This may be false but partition still be non-empty if it has a deletion.

    • getRow

      @Nullable Row getRow(Clustering<?> clustering)
      Returns the row corresponding to the provided clustering, or null if there is not such row.
      Parameters:
      clustering - clustering key to search
      Returns:
      row corresponding to the clustering, it's either null or non-empty row.

    • 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.

    • unfilteredIterator

      UnfilteredRowIterator unfilteredIterator(ColumnFilter columns, NavigableSet<Clustering<?>> clusteringsInQueryOrder, boolean reversed)
      Returns an UnfilteredRowIterator over the rows/RT contained by this partition selected by the provided clusterings.