com.thinkaurelius.titan.diskstorage.keycolumnvalue

Interface StoreFeatures

All Known Implementing Classes:

StandardStoreFeatures

public interface StoreFeatures

Describes features supported by a storage backend.

Author:

Matthias Broecheler (me@matthiasb.com), Dan LaRocque

Method Summary

Methods

Modifier and Type	Method and Description
Configuration	getKeyConsistentTxConfig() Get a transaction configuration that enforces key consistency.
Configuration	getLocalKeyConsistentTxConfig() Get a transaction configuration that enforces local key consistency.
boolean	hasBatchMutation() Whether this storage backend supports batch mutations via KeyColumnValueStoreManager.mutateMany(java.util.Map, StoreTransaction).
boolean	hasLocalKeyPartition()
boolean	hasLocking() Whether this store supports locking via KeyColumnValueStore.acquireLock(com.thinkaurelius.titan.diskstorage.StaticBuffer, com.thinkaurelius.titan.diskstorage.StaticBuffer, com.thinkaurelius.titan.diskstorage.StaticBuffer, StoreTransaction)
boolean	hasMultiQuery() Whether this storage backend supports query operations on multiple keys via KeyColumnValueStore.getSlice(java.util.List, SliceQuery, StoreTransaction)
boolean	hasOrderedScan() Whether this storage backend supports global key scans via KeyColumnValueStore.getKeys(KeyRangeQuery, StoreTransaction).
boolean	hasScan() Equivalent to calling hasUnorderedScan() || hasOrderedScan().
boolean	hasTimestamps() Returns true if column-value entries in this storage backend are annotated with a timestamp, else false.
boolean	hasTTL() Returns true if this storage backend support time-to-live (TTL) settings for column-value entries.
boolean	hasTxIsolation() Whether this storage backend's transactions support isolation.
boolean	hasUnorderedScan() Whether this storage backend supports global key scans via KeyColumnValueStore.getKeys(SliceQuery, StoreTransaction).
boolean	hasVisibility() Returns true if this storage backend supports entry-level visibility by attaching a visibility or authentication token to each column-value entry in the data store and limited retrievals to "visible" entries.
boolean	isDistributed() Whether this storage backend writes and reads data from more than one machine.
boolean	isKeyConsistent() Whether this storage backend provides strong consistency within each key/row.
boolean	isKeyOrdered() Whether this storage backend preserves key locality.

Method Detail

hasScan

boolean hasScan()

Equivalent to calling hasUnorderedScan() || hasOrderedScan().

hasUnorderedScan

boolean hasUnorderedScan()

Whether this storage backend supports global key scans via KeyColumnValueStore.getKeys(SliceQuery, StoreTransaction).

hasOrderedScan

boolean hasOrderedScan()

Whether this storage backend supports global key scans via KeyColumnValueStore.getKeys(KeyRangeQuery, StoreTransaction).

hasMultiQuery

boolean hasMultiQuery()

Whether this storage backend supports query operations on multiple keys via KeyColumnValueStore.getSlice(java.util.List, SliceQuery, StoreTransaction)

hasLocking

boolean hasLocking()

Whether this store supports locking via KeyColumnValueStore.acquireLock(com.thinkaurelius.titan.diskstorage.StaticBuffer, com.thinkaurelius.titan.diskstorage.StaticBuffer, com.thinkaurelius.titan.diskstorage.StaticBuffer, StoreTransaction)

hasBatchMutation

boolean hasBatchMutation()

Whether this storage backend supports batch mutations via KeyColumnValueStoreManager.mutateMany(java.util.Map, StoreTransaction).

isKeyOrdered

boolean isKeyOrdered()

Whether this storage backend preserves key locality. This affects Titan's use of vertex ID partitioning.

isDistributed

boolean isDistributed()

Whether this storage backend writes and reads data from more than one machine.

hasTxIsolation

boolean hasTxIsolation()

Whether this storage backend's transactions support isolation.

hasLocalKeyPartition

boolean hasLocalKeyPartition()

isKeyConsistent

boolean isKeyConsistent()

Whether this storage backend provides strong consistency within each key/row. This property is weaker than general strong consistency, since reads and writes to different keys need not obey strong consistency. "Key consistency" is shorthand for "strong consistency at the key/row level".

Returns:

true if the backend supports key-level strong consistency

hasTimestamps

boolean hasTimestamps()

Returns true if column-value entries in this storage backend are annotated with a timestamp, else false. It is assumed that the timestamp matches the one set during the committing transaction.

Returns:

hasTTL

boolean hasTTL()

Returns true if this storage backend support time-to-live (TTL) settings for column-value entries. If such a value is provided as a meta-data annotation on the Entry, the entry will disappear from the storage backend after the given amount of time.

Returns:

true if the storage backend supports TTL, else false

hasVisibility

boolean hasVisibility()

Returns true if this storage backend supports entry-level visibility by attaching a visibility or authentication token to each column-value entry in the data store and limited retrievals to "visible" entries.

Returns:

getKeyConsistentTxConfig

Configuration getKeyConsistentTxConfig()

Get a transaction configuration that enforces key consistency. This method has undefined behavior when isKeyConsistent() is false.

Returns:

a key-consistent tx config

getLocalKeyConsistentTxConfig

Configuration getLocalKeyConsistentTxConfig()

Get a transaction configuration that enforces local key consistency. "Local" has flexible meaning depending on the backend implementation. An example is Cassandra's notion of LOCAL_QUORUM, which provides strong consistency among all replicas in the same datacenter as the node handling the request, but not nodes at other datacenters. This method has undefined behavior when isKeyConsistent() is false. Backends which don't support the notion of "local" strong consistency may return the same configuration returned by #getKeyConsistencyTxConfig().

Returns:

a locally (or globally) key-consistent tx config