Package org.apache.cassandra.index

Class SingletonIndexQueryPlan

java.lang.Object

org.apache.cassandra.index.SingletonIndexQueryPlan

All Implemented Interfaces:

Comparable<Index.QueryPlan>, Index.QueryPlan

Direct Known Subclasses:

SASIIndexQueryPlan

public class SingletonIndexQueryPlan
extends Object
implements Index.QueryPlan

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	SingletonIndexQueryPlan(Index index, RowFilter postIndexFilter)

Method Summary

Modifier and Type	Method	Description
protected static SingletonIndexQueryPlan	create(Index index, RowFilter rowFilter)
long	getEstimatedResultRows()	Return an estimate of the number of results this plan is expected to return for any given ReadCommand that it can be used to answer.
Index	getFirst()	Returns the first index in this plan.
Set<Index>	getIndexes()	Returns the indexes selected by this query plan, all of them belonging to the same Index.Group.
RowFilter	postIndexQueryFilter()	Transform an initial RowFilter into the filter that will still need to applied to a set of Rows after the index has performed it's initial scan.
Index.Searcher	searcherFor(ReadCommand command)	Factory method for query time search helper.

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.QueryPlan

compareTo, isTopK, postProcessor, shouldEstimateInitialConcurrency, supportsReplicaFilteringProtection, validate

Constructor Details

SingletonIndexQueryPlan

protected SingletonIndexQueryPlan(Index index,
 RowFilter postIndexFilter)

Method Details

create

@Nullable
protected static SingletonIndexQueryPlan create(Index index,
 RowFilter rowFilter)

getIndexes

public Set<Index> getIndexes()

Description copied from interface: Index.QueryPlan

Returns the indexes selected by this query plan, all of them belonging to the same Index.Group. It should never be empty.

Specified by:

getIndexes in interface Index.QueryPlan

Returns:

the indexes selected by this query plan, which is never empty

getFirst

@Nonnull
public Index getFirst()

Description copied from interface: Index.QueryPlan

Returns the first index in this plan.

Specified by:

getFirst in interface Index.QueryPlan

Returns:

the first index

getEstimatedResultRows

public long getEstimatedResultRows()

Description copied from interface: Index.QueryPlan

Return an estimate of the number of results this plan is expected to return for any given ReadCommand that it can be used to answer. Used by SecondaryIndexManager.getBestIndexQueryPlanFor(RowFilter) to determine the Index.Group with the most selective plan for a given RowFilter. Additionally, this is also used by StorageProxy.estimateResultsPerRange to calculate the initial concurrency factor for range requests

Specified by:

getEstimatedResultRows in interface Index.QueryPlan

Returns:

the estimated average number of results a Searcher may return for any given command

searcherFor

public Index.Searcher searcherFor(ReadCommand command)

Description copied from interface: Index.QueryPlan

Factory method for query time search helper.

Specified by:

searcherFor in interface Index.QueryPlan

Parameters:

command - the read command being executed

Returns:

an Searcher with which to perform the supplied command

postIndexQueryFilter

public RowFilter postIndexQueryFilter()

Description copied from interface: Index.QueryPlan

Transform an initial RowFilter into the filter that will still need to applied to a set of Rows after the index has performed it's initial scan. Used in ReadCommand.executeLocally(ReadExecutionController) to reduce the amount of filtering performed on the results of the index query.

Specified by:

postIndexQueryFilter in interface Index.QueryPlan

Returns:

the (hopefully) reduced filter that would still need to be applied after the index was used to narrow the initial result set