Package org.apache.cassandra.index.internal.composites

Class CollectionValueIndex

java.lang.Object

org.apache.cassandra.index.internal.CassandraIndex

org.apache.cassandra.index.internal.composites.CollectionValueIndex

All Implemented Interfaces:

Index

public class CollectionValueIndex
extends CassandraIndex

Index the value of a collection cell. This is a lot like an index on REGULAR, except that we also need to make the collection key part of the index entry so that: 1) we don't have to scan the whole collection at query time to know the entry is stale and if it still satisfies the query. 2) if a collection has multiple time the same value, we need one entry for each so that if we delete one of the value only we only delete the entry corresponding to that value.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.cassandra.index.Index

Index.CollatedViewIndexBuildingSupport, Index.Group, Index.IndexBuildingSupport, Index.Indexer, Index.LoadType, Index.QueryPlan, Index.Searcher, Index.Status

Field Summary

Fields inherited from class org.apache.cassandra.index.internal.CassandraIndex

baseCfs, functions, indexCfs, indexedColumn, metadata, NAME

Fields inherited from interface org.apache.cassandra.index.Index

INDEX_BUILDER_SUPPORT

Constructor Summary

Constructors

Constructor	Description
CollectionValueIndex(ColumnFamilyStore baseCfs, IndexMetadata indexDef)

Method Summary

Modifier and Type	Method	Description
<T> CBuilder	buildIndexClusteringPrefix(ByteBuffer partitionKey, ClusteringPrefix<T> prefix, CellPath path)	Used to construct an the clustering for an entry in the index table based on values from the base data.
IndexEntry	decodeEntry(DecoratedKey indexedValue, Row indexEntry)	Used at search time to convert a row in the index table into a simple struct containing the values required to retrieve the corresponding row from the base table.
ByteBuffer	getIndexedValue(ByteBuffer partitionKey, Clustering<?> clustering, CellPath path, ByteBuffer cellValue)	Extract the value to be inserted into the index from the components of the base data
boolean	isStale(Row data, ByteBuffer indexValue, long nowInSec)	Check whether a value retrieved from an index is still valid by comparing it to current row from the base table.
boolean	supportsOperator(ColumnMetadata indexedColumn, Operator operator)	Returns true if an index of this type can support search predicates of the form [column] OPERATOR [value]

Methods inherited from class org.apache.cassandra.index.internal.CassandraIndex

customExpressionValueType, deleteStaleEntry, dependsOn, getBackingTable, getBlockingFlushTask, getEstimatedResultRows, getIndexCfs, getIndexComparator, getIndexedColumn, getIndexMetadata, getInitializationTask, getInvalidateTask, getMetadataReloadTask, getPostIndexQueryFilter, getTruncateTask, indexCfsMetadata, indexerFor, isQueryable, newIndex, register, searcherFor, shouldBuildBlocking, supportsExpression, validate, validate

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.cassandra.index.Index

filtersMultipleContains, getBlockingFlushTask, getBuildTaskSupport, getComponents, getFlushObserver, getPostQueryOrdering, getPreJoinTask, getRecoveryTaskSupport, getSupportedLoadTypeOnFailure, isSSTableAttached, notifyIndexerAboutRowsInFullyExpiredSSTables, unregister

Constructor Details

CollectionValueIndex

public CollectionValueIndex(ColumnFamilyStore baseCfs,
 IndexMetadata indexDef)

Method Details

getIndexedValue

public ByteBuffer getIndexedValue(ByteBuffer partitionKey,
 Clustering<?> clustering,
 CellPath path,
 ByteBuffer cellValue)

Description copied from class: CassandraIndex

Extract the value to be inserted into the index from the components of the base data

Specified by:

getIndexedValue in class CassandraIndex

Parameters:

partitionKey - from the primary data

clustering - from the primary data

path - from the primary data

cellValue - from the primary data

Returns:

a ByteBuffer containing the value to be inserted in the index. This will be used to make the partition key in the index table

buildIndexClusteringPrefix

public <T> CBuilder buildIndexClusteringPrefix(ByteBuffer partitionKey,
 ClusteringPrefix<T> prefix,
 CellPath path)

Description copied from class: CassandraIndex

Used to construct an the clustering for an entry in the index table based on values from the base data. The clustering columns in the index table encode the values required to retrieve the correct data from the base table and varies depending on the kind of the indexed column. See indexCfsMetadata for more details Used whenever a row in the index table is written or deleted.

Specified by:

buildIndexClusteringPrefix in class CassandraIndex

Parameters:

partitionKey - from the base data being indexed

prefix - from the base data being indexed

path - from the base data being indexed

Returns:

a clustering prefix to be used to insert into the index table

decodeEntry

public IndexEntry decodeEntry(DecoratedKey indexedValue,
 Row indexEntry)

Description copied from class: CassandraIndex

Used at search time to convert a row in the index table into a simple struct containing the values required to retrieve the corresponding row from the base table.

Specified by:

decodeEntry in class CassandraIndex

Parameters:

indexedValue - the partition key of the indexed table (i.e. the value that was indexed)

indexEntry - a row from the index table

Returns:

supportsOperator

public boolean supportsOperator(ColumnMetadata indexedColumn,
 Operator operator)

Description copied from class: CassandraIndex

Returns true if an index of this type can support search predicates of the form [column] OPERATOR [value]

Overrides:

supportsOperator in class CassandraIndex

Returns:

isStale

public boolean isStale(Row data,
 ByteBuffer indexValue,
 long nowInSec)

Description copied from class: CassandraIndex

Check whether a value retrieved from an index is still valid by comparing it to current row from the base table. Used at read time to identify out of date index entries so that they can be excluded from search results and repaired

Specified by:

isStale in class CassandraIndex

Parameters:

data - the current row from the primary data table

indexValue - the value we retrieved from the index

Returns:

true if the index is out of date and the entry should be dropped