Package org.apache.cassandra.index.sai.disk.v1.segment

Class Segment

java.lang.Object

org.apache.cassandra.index.sai.disk.v1.segment.Segment

All Implemented Interfaces:

Closeable, AutoCloseable, SegmentOrdering

public class Segment
extends Object
implements SegmentOrdering, Closeable

Each segment represents an on-disk index structure (balanced tree/terms/postings) flushed by memory limit or token boundaries. It also helps to reduce resource consumption for read requests as only segments that intersect with read request data range need to be loaded.

Field Summary

Fields

Modifier and Type	Field	Description
final SegmentMetadata	metadata

Constructor Summary

Constructors

Constructor	Description
Segment(Token minKey, Token maxKey)
Segment(StorageAttachedIndex index, SSTableContext sstableContext, PerColumnIndexFiles indexFiles, SegmentMetadata metadata)

Method Summary

Modifier and Type	Method	Description
void	close()
long	indexFileCacheSize()
boolean	intersects(AbstractBounds<PartitionPosition> keyRange)
CloseableIterator<PrimaryKeyWithScore>	orderBy(Expression orderer, AbstractBounds<PartitionPosition> keyRange, QueryContext context)	Order the on-disk index synchronously and produce an iterator in score order
CloseableIterator<PrimaryKeyWithScore>	orderResultsBy(QueryContext context, List<PrimaryKey> results, Expression orderer)	Reorder, limit, and put back into original order the results from a single sstable
KeyRangeIterator	search(Expression expression, AbstractBounds<PartitionPosition> keyRange, QueryContext context)	Search on-disk index synchronously
String	toString()

Methods inherited from class java.lang.Object

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

Field Details

metadata

public final SegmentMetadata metadata

Constructor Details

Segment

public Segment(StorageAttachedIndex index,
 SSTableContext sstableContext,
 PerColumnIndexFiles indexFiles,
 SegmentMetadata metadata)
        throws IOException

Throws:

IOException

Segment

public Segment(Token minKey,
 Token maxKey)

Method Details

intersects

public boolean intersects(AbstractBounds<PartitionPosition> keyRange)

Returns:

true if current segment intersects with query key range

indexFileCacheSize

public long indexFileCacheSize()

search

public KeyRangeIterator search(Expression expression,
 AbstractBounds<PartitionPosition> keyRange,
 QueryContext context)
                        throws IOException

Search on-disk index synchronously

Parameters:

expression - to filter on disk index

context - to track per sstable cache and per query metrics

Returns:

range iterator that matches given expression

Throws:

IOException

orderBy

public CloseableIterator<PrimaryKeyWithScore> orderBy(Expression orderer,
 AbstractBounds<PartitionPosition> keyRange,
 QueryContext context)
                                               throws IOException

Order the on-disk index synchronously and produce an iterator in score order

Parameters:

orderer - the expression to use when searching the on disk index

keyRange - key range specific in read command, used by ANN index

context - to track per sstable cache and per query metrics

Returns:

an iterator of PrimaryKeyWithScore in score order

Throws:

IOException

orderResultsBy

public CloseableIterator<PrimaryKeyWithScore> orderResultsBy(QueryContext context,
 List<PrimaryKey> results,
 Expression orderer)
                                                      throws IOException

Description copied from interface: SegmentOrdering

Reorder, limit, and put back into original order the results from a single sstable

Specified by:

orderResultsBy in interface SegmentOrdering

Throws:

IOException

close

public void close()

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

toString

public String toString()

Overrides:

toString in class Object