Package org.apache.druid.query

Interface Query<T>

All Known Implementing Classes:

BaseQuery, DataSourceMetadataQuery, GroupByQuery, ScanQuery, SearchQuery, SegmentMetadataQuery, SelectQuery, TimeBoundaryQuery, TimeseriesQuery, TopNQuery, UnionQuery, WindowOperatorQuery

public interface Query<T>

Field Summary

Fields

Modifier and Type	Field	Description
static final String	DATASOURCE_METADATA
static final String	GROUP_BY
static final String	SCAN
static final String	SEARCH
static final String	SEGMENT_METADATA
static final String	SELECT
static final String	TIME_BOUNDARY
static final String	TIMESERIES
static final String	TOPN
static final String	UNION_QUERY
static final String	WINDOW_OPERATOR

Method Summary

Modifier and Type	Method	Description
default QueryContext	context()	Returns the query context as a QueryContext, which provides convenience methods for accessing typed context values.
Map<String,Object>	getContext()	Returns the context as an (immutable) map.
default boolean	getContextBoolean(String key, boolean defaultValue)	Deprecated. use queryContext().getBoolean() instead.
default HumanReadableBytes	getContextHumanReadableBytes(String key, HumanReadableBytes defaultValue)	Deprecated. use queryContext().getContextHumanReadableBytes() instead.
default <ContextType> ContextType	getContextValue(String key)	Deprecated. use queryContext().get<Type>() instead
DataSource	getDataSource()
org.joda.time.Duration	getDuration()
DimFilter	getFilter()
Granularity	getGranularity()
String	getId()
List<org.joda.time.Interval>	getIntervals()
default String	getMostSpecificId()	Returns a most specific ID of this query; if it is a subquery, this will return its subquery ID.
default Set<String>	getRequiredColumns()	Returns the set of columns that this query will need to access out of its datasource.
com.google.common.collect.Ordering<T>	getResultOrdering()	Comparator that represents the order in which results are generated from the QueryRunnerFactory.createRunner(Segment) and QueryRunnerFactory.mergeRunners(QueryProcessingPool, Iterable) calls.
default RowSignature	getResultRowSignature()
default RowSignature	getResultRowSignature(RowSignature.Finalization finalization)
QueryRunner<T>	getRunner(QuerySegmentWalker walker)
default org.joda.time.Interval	getSingleInterval()	Returns an interval if getIntervals() has only a single interval, else explodes
default String	getSqlQueryId()
String	getSubQueryId()	Returns the subQueryId of this query.
org.joda.time.DateTimeZone	getTimezone()
String	getType()
default VirtualColumns	getVirtualColumns()
boolean	hasFilters()
default boolean	mayCollapseQueryDataSource()	Signals that the execution of this query could also transparently handle the input QueryDataSource as well.
default Query<T>	optimizeForSegment(PerSegmentQueryOptimizationContext optimizationContext)
Query<T>	withDataSource(DataSource dataSource)
default Query<T>	withDefaultSubQueryId()
Query<T>	withId(String id)
default Query<T>	withLane(String lane)
Query<T>	withOverriddenContext(Map<String,Object> contextOverride)
default Query<T>	withPriority(int priority)
Query<T>	withQuerySegmentSpec(QuerySegmentSpec spec)	Returns a new query, identical to this one, but with a different associated QuerySegmentSpec.
default Query<T>	withSqlQueryId(String sqlQueryId)
Query<T>	withSubQueryId(String subQueryId)	Returns a copy of this query with a new subQueryId (see getSubQueryId().

Field Details

DATASOURCE_METADATA

static final String DATASOURCE_METADATA

See Also:

• Constant Field Values

GROUP_BY

static final String GROUP_BY

See Also:

• Constant Field Values

SCAN

static final String SCAN

See Also:

• Constant Field Values

SEARCH

static final String SEARCH

See Also:

• Constant Field Values

SEGMENT_METADATA

static final String SEGMENT_METADATA

See Also:

• Constant Field Values

SELECT

static final String SELECT

See Also:

• Constant Field Values

TIME_BOUNDARY

static final String TIME_BOUNDARY

See Also:

• Constant Field Values

TIMESERIES

static final String TIMESERIES

See Also:

• Constant Field Values

TOPN

static final String TOPN

See Also:

• Constant Field Values

WINDOW_OPERATOR

static final String WINDOW_OPERATOR

See Also:

• Constant Field Values

UNION_QUERY

static final String UNION_QUERY

See Also:

• Constant Field Values

Method Details

getDataSource

DataSource getDataSource()

hasFilters

boolean hasFilters()

getFilter

DimFilter getFilter()

getType

String getType()

getRunner

QueryRunner<T> getRunner(QuerySegmentWalker walker)

getIntervals

List<org.joda.time.Interval> getIntervals()

getDuration

org.joda.time.Duration getDuration()

getGranularity

Granularity getGranularity()

getTimezone

org.joda.time.DateTimeZone getTimezone()

getContext

Map<String,Object> getContext()

Returns the context as an (immutable) map.

context

default QueryContext context()

Returns the query context as a QueryContext, which provides convenience methods for accessing typed context values. The returned instance is a view on top of the context provided by getContext().

The default implementation is for backward compatibility. Derived classes should store and return the QueryContext directly.

getContextValue

@Deprecated
@Nullable
default <ContextType> ContextType getContextValue(String key)

Deprecated.

use queryContext().get<Type>() instead

Get context value and cast to ContextType in an unsafe way.

For safe conversion, it's recommended to use following methods instead:

QueryContext.getBoolean(String)
QueryContext.getString(String)
QueryContext.getInt(String)
QueryContext.getLong(String)
QueryContext.getFloat(String)
QueryContext.getEnum(String, Class, Enum)
QueryContext.getHumanReadableBytes(String, HumanReadableBytes)

getContextBoolean

@Deprecated
default boolean getContextBoolean(String key,
 boolean defaultValue)

Deprecated.

use queryContext().getBoolean() instead.

getContextHumanReadableBytes

@Deprecated
default HumanReadableBytes getContextHumanReadableBytes(String key,
 HumanReadableBytes defaultValue)

Deprecated.

use queryContext().getContextHumanReadableBytes() instead.

Returns HumanReadableBytes for a specified context key. If the context is null or the key doesn't exist a caller specified default value is returned. A default implementation is provided since Query is an extension point. Extensions can choose to rely on this default to retain compatibility with core Druid.

Parameters:

key - The context key value being looked up

defaultValue - The default to return if the key value doesn't exist or the context is null.

Returns:

HumanReadableBytes

getResultOrdering

com.google.common.collect.Ordering<T> getResultOrdering()

Comparator that represents the order in which results are generated from the QueryRunnerFactory.createRunner(Segment) and QueryRunnerFactory.mergeRunners(QueryProcessingPool, Iterable) calls. This is used to combine streams of results from different sources; for example, it's used by historicals to combine streams from different segments, and it's used by the broker to combine streams from different historicals.

Important note: sometimes, this ordering is used in a type-unsafe way to order @{code Result} objects. Because of this, implementations should fall back to Ordering.natural() when they are given an object that is not of type T.

withOverriddenContext

Query<T> withOverriddenContext(Map<String,Object> contextOverride)

withQuerySegmentSpec

Query<T> withQuerySegmentSpec(QuerySegmentSpec spec)

Returns a new query, identical to this one, but with a different associated QuerySegmentSpec.

This often changes the behavior of getRunner(QuerySegmentWalker), since most queries inherit that method from BaseQuery, which implements it by calling QuerySegmentSpec.lookup(org.apache.druid.query.Query<T>, org.apache.druid.query.QuerySegmentWalker).

withId

Query<T> withId(String id)

getId

@Nullable
String getId()

withSubQueryId

Query<T> withSubQueryId(String subQueryId)

Returns a copy of this query with a new subQueryId (see getSubQueryId().

withDefaultSubQueryId

default Query<T> withDefaultSubQueryId()

getSubQueryId

@Nullable
String getSubQueryId()

Returns the subQueryId of this query. This is set by ClientQuerySegmentWalker (the entry point for the Broker's query stack) on any subqueries that it issues. It is null for the main query.

withSqlQueryId

default Query<T> withSqlQueryId(String sqlQueryId)

getSqlQueryId

@Nullable
default String getSqlQueryId()

getMostSpecificId

default String getMostSpecificId()

Returns a most specific ID of this query; if it is a subquery, this will return its subquery ID. If it is a regular query without subqueries, this will return its query ID. This method should be called after the relevant ID is assigned using withId(java.lang.String) or withSubQueryId(java.lang.String).

withDataSource

Query<T> withDataSource(DataSource dataSource)

optimizeForSegment

default Query<T> optimizeForSegment(PerSegmentQueryOptimizationContext optimizationContext)

withPriority

default Query<T> withPriority(int priority)

withLane

default Query<T> withLane(String lane)

getVirtualColumns

default VirtualColumns getVirtualColumns()

getRequiredColumns

@Nullable
default Set<String> getRequiredColumns()

Returns the set of columns that this query will need to access out of its datasource.

This method does not "look into" what the datasource itself is doing. For example, if a query is built on a QueryDataSource, this method will not return the columns used by that subquery. As another example, if a query is built on a JoinDataSource, this method will not return the columns from the underlying datasources that are used by the join condition, unless those columns are also used by this query in other ways.

Returns null if the set of required columns cannot be known ahead of time.

getSingleInterval

default org.joda.time.Interval getSingleInterval()

Returns an interval if getIntervals() has only a single interval, else explodes

mayCollapseQueryDataSource

default boolean mayCollapseQueryDataSource()

Signals that the execution of this query could also transparently handle the input QueryDataSource as well. This is a not-so-nice way to support that GroupByQuery could collapse other GroupByQuery-ies in QueryDataSource-es.

getResultRowSignature

default RowSignature getResultRowSignature()

getResultRowSignature

default RowSignature getResultRowSignature(RowSignature.Finalization finalization)