org.apache.cassandra.io.sstable
Class SSTableMetadata

java.lang.Object
  org.apache.cassandra.io.sstable.SSTableMetadata

public class SSTableMetadata
extends java.lang.Object

Metadata for a SSTable. Metadata includes: - estimated row size histogram - estimated column count histogram - replay position - max column timestamp - compression ratio - partitioner - generations of sstables from which this sstable was compacted, if any - tombstone drop time histogram An SSTableMetadata should be instantiated via the Collector, openFromDescriptor() or createDefaultInstance()

Nested Class Summary

static class	SSTableMetadata.Collector
static class	SSTableMetadata.SSTableMetadataSerializer

Field Summary

java.util.Set<java.lang.Integer>	ancestors
double	compressionRatio
EstimatedHistogram	estimatedColumnCount
EstimatedHistogram	estimatedRowSize
StreamingHistogram	estimatedTombstoneDropTime
long	maxTimestamp
long	minTimestamp
static double	NO_COMPRESSION_RATIO
java.lang.String	partitioner
ReplayPosition	replayPosition
static SSTableMetadata.SSTableMetadataSerializer	serializer

Method Summary

static SSTableMetadata.Collector	createCollector()
double	getDroppableTombstonesBefore(int gcBefore) Get the amount of droppable tombstones
double	getEstimatedDroppableTombstoneRatio(int gcBefore)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NO_COMPRESSION_RATIO

public static final double NO_COMPRESSION_RATIO

See Also:

Constant Field Values

serializer

public static final SSTableMetadata.SSTableMetadataSerializer serializer

estimatedRowSize

public final EstimatedHistogram estimatedRowSize

estimatedColumnCount

public final EstimatedHistogram estimatedColumnCount

replayPosition

public final ReplayPosition replayPosition

minTimestamp

public final long minTimestamp

maxTimestamp

public final long maxTimestamp

compressionRatio

public final double compressionRatio

partitioner

public final java.lang.String partitioner

ancestors

public final java.util.Set<java.lang.Integer> ancestors

estimatedTombstoneDropTime

public final StreamingHistogram estimatedTombstoneDropTime

Method Detail

createCollector

public static SSTableMetadata.Collector createCollector()

getEstimatedDroppableTombstoneRatio

public double getEstimatedDroppableTombstoneRatio(int gcBefore)

Parameters:

gcBefore -

Returns:

estimated droppable tombstone ratio at given gcBefore time.

getDroppableTombstonesBefore

public double getDroppableTombstonesBefore(int gcBefore)

Get the amount of droppable tombstones

Parameters:

gcBefore - the gc time

Returns:

amount of droppable tombstones