# Package org.apache.cassandra.db

Interface Summary
BatchlogManagerMBean
BlacklistedDirectoriesMBean
Cell: Cell is immutable, which prevents all kinds of confusion in a multithreaded environment.
ColumnFamilyStoreMBean: The MBean interface for ColumnFamilyStore
CounterCell: A column that represents a partitioned counter.
CounterUpdateCell: A counter update while it hasn't been applied yet by the leader replica.
DeletedCell
ExpiringCell: Alternative to Cell that have an expiring time.
HintedHandOffManagerMBean
IMutation
OnDiskAtom
OnDiskAtom.SerializerForWriting
RowIndexEntry.IndexSerializer<T>
RowPosition

Class Summary
AbstractCell
AbstractNativeCell: {@code Packs a CellName AND a Cell into one off-heap representation.
AbstractRangeCommand
ArrayBackedSortedColumns: A ColumnFamily backed by an array.
AtomDeserializer: Helper class to deserialize OnDiskAtom efficiently.
AtomicBTreeColumns: A thread-safe and atomic ISortedColumns implementation.
BatchlogManager
BatchlogManager.EndpointFilter
BlacklistedDirectories
BufferCell
BufferCounterCell
BufferCounterUpdateCell
BufferDecoratedKey
BufferDeletedCell
BufferExpiringCell
CachedHashDecoratedKey
CFRowAdder: Convenience object to populate a given CQL3 row in a ColumnFamily object.
ClockAndCount
CollationController
ColumnFamily: A sorted map of columns.
ColumnFamily.Factory<T extends ColumnFamily>
ColumnFamilySerializer
ColumnFamilyStore
ColumnFamilyStore.AbstractScanIterator
ColumnFamilyStore.FlushLargestColumnFamily: Finds the largest memtable, as a percentage of *either* on- or off-heap memory limits, and immediately queues it for flushing.
ColumnFamilyStore.RefViewFragment
ColumnFamilyStore.ViewFragment
ColumnIndex
ColumnIndex.Builder: Help to create an index for a column family based on size of columns, and write said columns to disk.
ColumnSerializer
CounterMutation
CounterMutation.CounterMutationSerializer
CounterMutationVerbHandler
DataRange: Groups key range and column filter for range queries.
DataRange.Paging
DecoratedKey: Represents a decorated key, handy for certain operations where just working with strings gets slow.
DefinitionsUpdateVerbHandler: Called when node receives updated schema state from the schema migration coordinator node.
DeletionInfo: A combination of a top-level (or row) tombstone and range tombstones describing the deletions within a `ColumnFamily` (or row).
DeletionInfo.Serializer
DeletionTime: A top-level (row) tombstone.
DeletionTime.Serializer
Directories: Encapsulate handling of paths to the data files.
Directories.DataDirectory

HintedHandOffManager

The hint schema looks like this: CREATE TABLE hints ( target_id uuid, hint_id timeuuid, message_version int, mutation blob, PRIMARY KEY (target_id, hint_id, message_version) ) WITH COMPACT STORAGE; Thus, for each node in the cluster we treat its uuid as the partition key; each hint is a logical row (physical composite column) containing the mutation to replay and associated metadata.

IndexExpression
Keyspace: It represents a Keyspace.
Memtable
Memtable.LastReplayPosition
MigrationRequestVerbHandler: Sends it's current schema state in form of mutations in reply to the remote node's request.
Mutation
Mutation.MutationSerializer
MutationVerbHandler
NativeCell
NativeCounterCell
NativeDecoratedKey
NativeDeletedCell
NativeExpiringCell
OnDiskAtom.Serializer
PagedRangeCommand
PreHashedDecoratedKey
RangeSliceCommand
RangeSliceReply
RangeTombstone
RangeTombstone.Serializer
RangeTombstone.Tracker: Tracks opened RangeTombstones when iterating over a partition.
RangeTombstoneList: Data structure holding the range tombstones of a ColumnFamily.
RangeTombstoneList.Serializer
ReadCommand
ReadRepairVerbHandler
ReadResponse
ReadVerbHandler
RetriedSliceFromReadCommand
Row
Row.RowSerializer
RowIndexEntry<T>
RowIndexEntry.Serializer
RowIteratorFactory
RowPosition.ForKey
RowPosition.RowPositionSerializer
SchemaCheckVerbHandler
SizeEstimatesRecorder: A very simplistic/crude partition count/size estimator.
SliceByNamesReadCommand
SliceFromReadCommand
SnapshotCommand
SnapshotDetailsTabularData
SuperColumns
SystemKeyspace
TruncateResponse: This message is sent back the truncate operation and basically specifies if the truncate succeeded.
TruncateResponse.TruncateResponseSerializer
TruncateVerbHandler
Truncation: A truncate operation descriptor
TypeSizes
TypeSizes.NativeDBTypeSizes
TypeSizes.VIntEncodedTypeSizes
WindowsFailedSnapshotTracker
WriteResponse
WriteResponse.WriteResponseSerializer

Enum Summary
ColumnFamilyType: column family type enum
ColumnSerializer.Flag: Flag affecting deserialization behavior.
ConsistencyLevel
Directories.FileAction
ReadCommand.Type
RowPosition.Kind
SystemKeyspace.BootstrapState
WriteType

Exception Summary
ColumnSerializer.CorruptColumnException
KeyspaceNotDefinedException
UnknownColumnFamilyException