Package org.apache.cassandra.index.sai.plan

Class QueryController

java.lang.Object

org.apache.cassandra.index.sai.plan.QueryController

public class QueryController
extends java.lang.Object

Constructor Summary

Constructors

Constructor	Description
QueryController(ColumnFamilyStore cfs, ReadCommand command, RowFilter indexFilter, QueryContext queryContext)

Method Summary

Modifier and Type	Method	Description
java.util.List<DataRange>	dataRanges()
boolean	doesNotSelect(PrimaryKey key)	Returns whether this query is not selecting the PrimaryKey.
PrimaryKey	firstPrimaryKeyInRange()
KeyRangeIterator.Builder	getIndexQueryResults(java.util.Collection<Expression> expressions)	Build a KeyRangeIterator.Builder from the given list of Expressions.
KeyRangeIterator	getTopKRows(RowFilter.Expression expression)
KeyRangeIterator	getTopKRows(KeyRangeIterator source, RowFilter.Expression expression)
boolean	hasAnalyzer(RowFilter.Expression expression)
RowFilter	indexFilter()
StorageAttachedIndex	indexFor(RowFilter.Expression expression)
PrimaryKey	lastPrimaryKeyInRange()
TableMetadata	metadata()
PrimaryKey.Factory	primaryKeyFactory()
UnfilteredRowIterator	queryStorage(PrimaryKey key, ReadExecutionController executionController)
boolean	usesStrictFiltering()

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryController

public QueryController(ColumnFamilyStore cfs,
                       ReadCommand command,
                       RowFilter indexFilter,
                       QueryContext queryContext)

Method Detail

primaryKeyFactory

public PrimaryKey.Factory primaryKeyFactory()

firstPrimaryKeyInRange

public PrimaryKey firstPrimaryKeyInRange()

lastPrimaryKeyInRange

public PrimaryKey lastPrimaryKeyInRange()

metadata

public TableMetadata metadata()

indexFilter

public RowFilter indexFilter()

usesStrictFiltering

public boolean usesStrictFiltering()

dataRanges

public java.util.List<DataRange> dataRanges()

Returns:

token ranges used in the read command

indexFor

@Nullable
public StorageAttachedIndex indexFor(RowFilter.Expression expression)

hasAnalyzer

public boolean hasAnalyzer(RowFilter.Expression expression)

queryStorage

public UnfilteredRowIterator queryStorage(PrimaryKey key,
                                          ReadExecutionController executionController)

getIndexQueryResults

public KeyRangeIterator.Builder getIndexQueryResults(java.util.Collection<Expression> expressions)

Build a KeyRangeIterator.Builder from the given list of Expressions.

This is achieved by creating an on-disk view of the query that maps the expressions to the SSTableIndexs that will satisfy the expression.

Each (expression, SSTable indexes) pair is then passed to IndexSearchResultIterator.build(Expression, Collection, AbstractBounds, QueryContext, boolean, Runnable) to search the in-memory index associated with the expression and the SSTable indexes, the results of which are unioned and returned.

The results from each call to IndexSearchResultIterator.build(Expression, Collection, AbstractBounds, QueryContext, boolean, Runnable) are added to a KeyRangeIntersectionIterator and returned if strict filtering is allowed.

If strict filtering is not allowed, indexes are split into two groups according to the repaired status of their backing SSTables. Results from searches over the repaired group are added to a KeyRangeIntersectionIterator, which is then added, along with results from searches on the unrepaired set, to a top-level KeyRangeUnionIterator, and returned. This is done to ensure that AND queries do not prematurely filter out matches on un-repaired partial updates. Post-filtering must also take this into account. (see FilterTree.isSatisfiedBy(DecoratedKey, Row, Row)) Note that Memtable-attached indexes are treated as part of the unrepaired set.

doesNotSelect

public boolean doesNotSelect(PrimaryKey key)

Returns whether this query is not selecting the PrimaryKey. The query does not select the key if both of the following statements are false: 1. The table associated with the query is not using clustering keys 2. The clustering index filter for the command wants the row.

Item 2 is important in paged queries where the ClusteringIndexSliceFilter for subsequent paged queries may not select rows that are returned by the index search because that is initially partition based.

Parameters:

key - The PrimaryKey to be tested

Returns:

true if the key is not selected by the query

getTopKRows

public KeyRangeIterator getTopKRows(RowFilter.Expression expression)

getTopKRows

public KeyRangeIterator getTopKRows(KeyRangeIterator source,
                                    RowFilter.Expression expression)