org.apache.druid.query.scan

Class ScanQuery

java.lang.Object

org.apache.druid.query.BaseQuery<ScanResultValue>

org.apache.druid.query.scan.ScanQuery

All Implemented Interfaces:

Query<ScanResultValue>

public class ScanQuery
extends BaseQuery<ScanResultValue>

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ScanQuery.Order
static class	ScanQuery.OrderBy
static class	ScanQuery.ResultFormat

Field Summary

Fields

Modifier and Type	Field and Description
static String	CTX_KEY_OUTERMOST This context flag corresponds to whether the query is running on the "outermost" process (i.e.
static int	DEFAULT_BATCH_SIZE

Fields inherited from class org.apache.druid.query.BaseQuery

QUERY_ID, SQL_QUERY_ID, SUB_QUERY_ID

Fields inherited from interface org.apache.druid.query.Query

DATASOURCE_METADATA, GROUP_BY, SCAN, SEARCH, SEGMENT_METADATA, SELECT, TIME_BOUNDARY, TIMESERIES, TOPN, WINDOW_OPERATOR

Constructor Summary

Constructors

Constructor and Description
ScanQuery(DataSource dataSource, QuerySegmentSpec querySegmentSpec, VirtualColumns virtualColumns, ScanQuery.ResultFormat resultFormat, int batchSize, long scanRowsOffset, long scanRowsLimit, ScanQuery.Order orderFromUser, List<ScanQuery.OrderBy> orderBysFromUser, DimFilter dimFilter, List<String> columns, Boolean legacy, Map<String,Object> context)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
int	getBatchSize()
List<String>	getColumns()
DimFilter	getFilter()
Integer	getMaxRowsQueuedForOrdering()
Integer	getMaxSegmentPartitionsOrderedInMemory()
List<ScanQuery.OrderBy>	getOrderBys()
Set<String>	getRequiredColumns() Returns the set of columns that this query will need to access out of its datasource.
ScanQuery.ResultFormat	getResultFormat()
com.google.common.collect.Ordering<ScanResultValue>	getResultOrdering() Default implementation of Query.getResultOrdering() that uses Ordering.natural().
long	getScanRowsLimit() Limit for this query; behaves like SQL "LIMIT".
long	getScanRowsOffset() Offset for this query; behaves like SQL "OFFSET".
ScanQuery.Order	getTimeOrder() If this query is purely-time-ordered, returns a value of the enum ScanQuery.Order.
String	getType()
VirtualColumns	getVirtualColumns()
boolean	hasFilters()
int	hashCode()
Boolean	isLegacy() Compatibility mode with the legacy scan-query extension.
boolean	isLimited() Returns whether this query is limited or not.
String	toString()
static void	verifyOrderByForNativeExecution(ScanQuery query) Verifies that the ordering of a query is solely determined by getTimeOrder().
ScanQuery	withDataSource(DataSource dataSource)
ScanQuery	withLimit(long newLimit)
ScanQuery	withNonNullLegacy(ScanQueryConfig scanQueryConfig)
ScanQuery	withOffset(long newOffset)
ScanQuery	withOverriddenContext(Map<String,Object> contextOverrides)
ScanQuery	withQuerySegmentSpec(QuerySegmentSpec querySegmentSpec) Returns a new query, identical to this one, but with a different associated QuerySegmentSpec.

Methods inherited from class org.apache.druid.query.BaseQuery

checkInterrupted, computeOverriddenContext, computeOverridenContext, context, getContext, getDataSource, getDuration, getGranularity, getId, getIntervals, getQuerySegmentSpec, getQuerySegmentSpecForLookUp, getRunner, getSubQueryId, getTimezone, isDescending, withId, withSqlQueryId, withSubQueryId

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.druid.query.Query

getContextBoolean, getContextHumanReadableBytes, getContextValue, getMostSpecificId, getSqlQueryId, optimizeForSegment, withDefaultSubQueryId, withLane, withPriority

Field Detail

CTX_KEY_OUTERMOST

public static final String CTX_KEY_OUTERMOST

This context flag corresponds to whether the query is running on the "outermost" process (i.e. the process the query is sent to).

See Also:

Constant Field Values

DEFAULT_BATCH_SIZE

public static final int DEFAULT_BATCH_SIZE

See Also:

Constant Field Values

Constructor Detail

ScanQuery

public ScanQuery(DataSource dataSource,
                 QuerySegmentSpec querySegmentSpec,
                 VirtualColumns virtualColumns,
                 ScanQuery.ResultFormat resultFormat,
                 int batchSize,
                 long scanRowsOffset,
                 long scanRowsLimit,
                 ScanQuery.Order orderFromUser,
                 List<ScanQuery.OrderBy> orderBysFromUser,
                 DimFilter dimFilter,
                 List<String> columns,
                 Boolean legacy,
                 Map<String,Object> context)

Method Detail

verifyOrderByForNativeExecution

public static void verifyOrderByForNativeExecution(ScanQuery query)

Verifies that the ordering of a query is solely determined by getTimeOrder(). Required to actually execute queries, because getOrderBys() is not yet understood by the query engines.

Throws:

IllegalStateException - if the ordering is not solely determined by getTimeOrder()

getVirtualColumns

public VirtualColumns getVirtualColumns()

getResultFormat

public ScanQuery.ResultFormat getResultFormat()

getBatchSize

public int getBatchSize()

getScanRowsOffset

public long getScanRowsOffset()

Offset for this query; behaves like SQL "OFFSET". Zero means no offset. Negative values are invalid.

getScanRowsLimit

public long getScanRowsLimit()

Limit for this query; behaves like SQL "LIMIT". Will always be positive. Long.MAX_VALUE is used in situations where the user wants an effectively unlimited result set.

isLimited

public boolean isLimited()

Returns whether this query is limited or not. Because Long.MAX_VALUE is used to signify unlimitedness, this is equivalent to getScanRowsLimit() != Long.Max_VALUE.

See Also:

getScanRowsLimit()

getTimeOrder

public ScanQuery.Order getTimeOrder()

If this query is purely-time-ordered, returns a value of the enum ScanQuery.Order. Otherwise, returns ScanQuery.Order.NONE. If the returned value is ScanQuery.Order.NONE it may not agree with getOrderBys().

getOrderBys

public List<ScanQuery.OrderBy> getOrderBys()

getMaxRowsQueuedForOrdering

@Nullable
public Integer getMaxRowsQueuedForOrdering()

getMaxSegmentPartitionsOrderedInMemory

@Nullable
public Integer getMaxSegmentPartitionsOrderedInMemory()

hasFilters

public boolean hasFilters()

getFilter

@Nullable
public DimFilter getFilter()

getType

public String getType()

getColumns

@Nullable
public List<String> getColumns()

isLegacy

@Nullable
public Boolean isLegacy()

Compatibility mode with the legacy scan-query extension. True, false, and null have different meanings: true/false mean "legacy" and "not legacy"; null means use the default set by ScanQueryConfig.isLegacy(). The method withNonNullLegacy(org.apache.druid.query.scan.ScanQueryConfig) is provided to help with this.

getResultOrdering

public com.google.common.collect.Ordering<ScanResultValue> getResultOrdering()

Description copied from class: BaseQuery

Default implementation of Query.getResultOrdering() that uses Ordering.natural(). If your query result type T is not Comparable, you must override this method.

Specified by:

getResultOrdering in interface Query<ScanResultValue>

Overrides:

getResultOrdering in class BaseQuery<ScanResultValue>

getRequiredColumns

@Nullable
public Set<String> getRequiredColumns()

Description copied from interface: Query

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.

withOffset

public ScanQuery withOffset(long newOffset)

withLimit

public ScanQuery withLimit(long newLimit)

withNonNullLegacy

public ScanQuery withNonNullLegacy(ScanQueryConfig scanQueryConfig)

withQuerySegmentSpec

public ScanQuery withQuerySegmentSpec(QuerySegmentSpec querySegmentSpec)

Description copied from interface: Query

Returns a new query, identical to this one, but with a different associated QuerySegmentSpec. This often changes the behavior of Query.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).

withDataSource

public ScanQuery withDataSource(DataSource dataSource)

withOverriddenContext

public ScanQuery withOverriddenContext(Map<String,Object> contextOverrides)

equals

public boolean equals(Object o)

Overrides:

equals in class BaseQuery<ScanResultValue>

hashCode

public int hashCode()

Overrides:

hashCode in class BaseQuery<ScanResultValue>

toString

public String toString()

Overrides:

toString in class Object