com.apple.foundationdb.record.query.plan.plans

Class RecordQueryUnorderedUnionPlan

java.lang.Object

com.apple.foundationdb.record.query.plan.plans.RecordQueryUnorderedUnionPlan

All Implemented Interfaces:

PlanHashable, QueryPlan<FDBQueriedRecord<Message>>, RecordQueryPlan, RecordQueryPlanWithChildren, Bindable, RelationalExpressionWithChildren, RelationalPlannerExpression, PlannerExpression

@API(value=EXPERIMENTAL)
public class RecordQueryUnorderedUnionPlan
extends Object

A query plan that returns results from two-or-more cursors as they as ready. Unlike the RecordQueryUnionPlan, there are no ordering restrictions placed on the child plans (i.e., the children are free to return results in any order). However, this plan also makes no effort to remove duplicates from its children, and it also makes no guarantees as to what order it will return results.

Field Summary

Fields

Modifier and Type	Field and Description
static org.slf4j.Logger	LOGGER
protected static String	UNION

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
boolean	equalsWithoutChildren(PlannerExpression otherExpression)
<M extends Message> RecordCursor<FDBQueriedRecord<M>>	execute(FDBRecordStoreBase<M> store, EvaluationContext context, byte[] continuation, ExecuteProperties executeProperties) Execute this query plan.
static RecordQueryUnorderedUnionPlan	from(List<RecordQueryPlan> children)
static RecordQueryUnorderedUnionPlan	from(RecordQueryPlan left, RecordQueryPlan right)
static RecordQueryUnorderedUnionPlan	fromRefs(ExpressionRef<RecordQueryPlan> left, ExpressionRef<RecordQueryPlan> right)
static RecordQueryUnorderedUnionPlan	fromRefs(List<ExpressionRef<RecordQueryPlan>> children)
List<RecordQueryPlan>	getChildren() Returns the (zero or more) RecordQueryPlan children of this plan.
int	getComplexity() Returns an integer representing the "complexity" of the generated plan.
Iterator<? extends ExpressionRef<? extends PlannerExpression>>	getPlannerExpressionChildren() Return an iterator of references to the children of this planner expression.
int	getRelationalChildCount()
Set<String>	getUsedIndexes() Returns a set of names of the indexes used by this plan (and its sub-plans).
boolean	hasFullRecordScan() Indicates whether this plan (or one of its components) must perform a scan over all records in the store directly rather than going through a secondary index.
int	hashCode()
boolean	hasIndexScan(String indexName) Indicates whether this plan scans the given index.
boolean	hasRecordScan() Indicates whether this plan (or one of its components) scans at least a subset of the record range directly rather than going through a secondary index.
boolean	isReverse() Indicates whether this plan will return values in "reverse" order from the natural order of results of this plan.
void	logPlanStructure(StoreTimer timer) Adds one to an appropriate StoreTimer counter for each plan and subplan of this plan, allowing tracking of which plans are being chosen (e.g.
int	planHash() Return a hash similar to hashCode, but with the additional guarantee that is is stable across JVMs.
String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.apple.foundationdb.record.query.plan.plans.RecordQueryPlan

asNestedWith, asUnnestedWith, execute, execute, execute, getQueryPlanChildren

Methods inherited from interface com.apple.foundationdb.record.query.plan.plans.QueryPlan

execute, execute

Methods inherited from interface com.apple.foundationdb.record.PlanHashable

combineHashes, iterablePlanHash, objectPlanHash, objectsPlanHash, planHash, planHash, planHashUnordered, stringHashUnordered

Methods inherited from interface com.apple.foundationdb.record.query.plan.temp.expressions.RelationalPlannerExpression

fromRecordQuery

Methods inherited from interface com.apple.foundationdb.record.query.plan.temp.PlannerExpression

acceptPropertyVisitor, bindTo

Field Detail

LOGGER

public static final org.slf4j.Logger LOGGER

UNION

protected static final String UNION

See Also:

Constant Field Values

Method Detail

toString

@Nonnull
public String toString()

from

@Nonnull
public static RecordQueryUnorderedUnionPlan from(@Nonnull
                                                          List<RecordQueryPlan> children)

from

@Nonnull
public static RecordQueryUnorderedUnionPlan from(@Nonnull
                                                          RecordQueryPlan left,
                                                          @Nonnull
                                                          RecordQueryPlan right)

fromRefs

@API(value=EXPERIMENTAL)
 @Nonnull
public static RecordQueryUnorderedUnionPlan fromRefs(@Nonnull
                                                                                        List<ExpressionRef<RecordQueryPlan>> children)

fromRefs

@API(value=EXPERIMENTAL)
 @Nonnull
public static RecordQueryUnorderedUnionPlan fromRefs(@Nonnull
                                                                                        ExpressionRef<RecordQueryPlan> left,
                                                                                        @Nonnull
                                                                                        ExpressionRef<RecordQueryPlan> right)

equalsWithoutChildren

@API(value=EXPERIMENTAL)
public boolean equalsWithoutChildren(@Nonnull
                                                              PlannerExpression otherExpression)

execute

@Nonnull
public <M extends Message> RecordCursor<FDBQueriedRecord<M>> execute(@Nonnull
                                                                              FDBRecordStoreBase<M> store,
                                                                              @Nonnull
                                                                              EvaluationContext context,
                                                                              @Nullable
                                                                              byte[] continuation,
                                                                              @Nonnull
                                                                              ExecuteProperties executeProperties)

Description copied from interface: RecordQueryPlan

Execute this query plan.

Specified by:

execute in interface RecordQueryPlan

Type Parameters:

M - type used to represent stored records

Parameters:

store - record store from which to fetch records

context - evaluation context containing parameter bindings

continuation - continuation from a previous execution of this same plan

executeProperties - limits on execution

Returns:

a cursor of records that match the query criteria

isReverse

public boolean isReverse()

Description copied from interface: QueryPlan

Indicates whether this plan will return values in "reverse" order from the natural order of results of this plan. The return value is true if the plan returns elements in descending order and false if the elements are returned in ascending order.

Specified by:

isReverse in interface QueryPlan<FDBQueriedRecord<Message>>

Returns:

true if this plan returns elements in reverse order

hasRecordScan

public boolean hasRecordScan()

Description copied from interface: QueryPlan

Indicates whether this plan (or one of its components) scans at least a subset of the record range directly rather than going through a secondary index. A plan may only scan over a subset of all records. Someone might not use any secondary indexes explicitly, but they might make use of the primary key index. For example, if they had a compound primary key, and they issued a query for all records that had some value for the first element of their primary key, the planner will produce a plan which scans over a subset of all records.

Specified by:

hasRecordScan in interface QueryPlan<FDBQueriedRecord<Message>>

Returns:

true if this plan (or one of its components) scans at least a subset of the records directly

hasFullRecordScan

public boolean hasFullRecordScan()

Description copied from interface: QueryPlan

Indicates whether this plan (or one of its components) must perform a scan over all records in the store directly rather than going through a secondary index. See hasRecordScan for the comparison between two methods.

Specified by:

hasFullRecordScan in interface QueryPlan<FDBQueriedRecord<Message>>

Returns:

true if this plan (or one of its components) must perform a scan over all records in the store directly

hasIndexScan

public boolean hasIndexScan(@Nonnull
                            String indexName)

Description copied from interface: QueryPlan

Indicates whether this plan scans the given index.

Specified by:

hasIndexScan in interface QueryPlan<FDBQueriedRecord<Message>>

Parameters:

indexName - the name of the index to check for

Returns:

true if this plan (or one of its children) scans the given index

getChildren

@Nonnull
public List<RecordQueryPlan> getChildren()

Description copied from interface: RecordQueryPlan

Returns the (zero or more) RecordQueryPlan children of this plan.

Warning: This part of the API is undergoing active development. At some point in the future, the return type of this method will change to allow it to return a list of generic QueryPlans. At current, every RecordQueryPlan can only have other RecordQueryPlans as children. However, this is not guaranteed to be the case in the future. This method has been marked as API.Status#UNSTABLE as of version 2.5.

Specified by:

getChildren in interface RecordQueryPlan

Returns:

the child plans

getUsedIndexes

@Nonnull
public Set<String> getUsedIndexes()

Description copied from interface: QueryPlan

Returns a set of names of the indexes used by this plan (and its sub-plans).

Specified by:

getUsedIndexes in interface QueryPlan<FDBQueriedRecord<Message>>

Returns:

an set of indexes used by this plan

getPlannerExpressionChildren

@Nonnull
 @API(value=EXPERIMENTAL)
public Iterator<? extends ExpressionRef<? extends PlannerExpression>> getPlannerExpressionChildren()

Description copied from interface: PlannerExpression

Return an iterator of references to the children of this planner expression. The iterators returned by different calls are guaranteed to be independent (i.e., advancing one will not advance another). However, they might point to the same object, as when Collections.emptyIterator() is returned. The returned iterator should be treated as an immutable object and may throw an exception if Iterator.remove() is called. The iterator must return its elements in a consistent order.

Specified by:

getPlannerExpressionChildren in interface PlannerExpression

Returns:

an iterator of references to the children of this planner expression

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

planHash

public int planHash()

Description copied from interface: PlanHashable

Return a hash similar to hashCode, but with the additional guarantee that is is stable across JVMs.

Specified by:

planHash in interface PlanHashable

Returns:

a stable hash code

logPlanStructure

public void logPlanStructure(StoreTimer timer)

Description copied from interface: QueryPlan

Adds one to an appropriate StoreTimer counter for each plan and subplan of this plan, allowing tracking of which plans are being chosen (e.g. index scan vs. full scan).

Specified by:

logPlanStructure in interface QueryPlan<FDBQueriedRecord<Message>>

Parameters:

timer - the counters to increment

getComplexity

public int getComplexity()

Description copied from interface: QueryPlan

Returns an integer representing the "complexity" of the generated plan. Currently, this should simply be the number of plans in the plan tree with this plan as the root (i.e. the number of descendants of this plan, including itself).

Specified by:

getComplexity in interface QueryPlan<FDBQueriedRecord<Message>>

Returns:

the complexity of this plan

getRelationalChildCount

public int getRelationalChildCount()

Specified by:

getRelationalChildCount in interface RelationalExpressionWithChildren