Package com.apple.foundationdb.record.query.plan

Interface QueryPlanner

All Known Implementing Classes:

CascadesPlanner, RecordQueryPlanner

@API(STABLE)
public interface QueryPlanner

A common interface for classes that can plan a RecordQuery into a RecordQueryPlan. The common interface allows tests to be run against several planners.

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	QueryPlanner.IndexScanPreference	Preference between index scan and record scan.

Method Summary

Modifier and Type	Method	Description
RecordMetaData	getRecordMetaData()	Get the RecordMetaData for this planner.
RecordStoreState	getRecordStoreState()	Get the RecordStoreState for this planner.
RecordQueryPlan	plan(RecordQuery query)	Create a plan to get the results of the provided query.
QueryPlanResult	planQuery(RecordQuery query)	Create a plan to get the results of the provided query.
void	setIndexScanPreference(QueryPlanner.IndexScanPreference indexScanPreference)	Set whether RecordQueryIndexPlan is preferred over RecordQueryScanPlan even when it does not satisfy any additional conditions.

Method Detail

plan

@Nonnull
RecordQueryPlan plan(@Nonnull
                     RecordQuery query)

Create a plan to get the results of the provided query.

Parameters:

query - a query for records on this planner's metadata

Returns:

a plan that will return the results of the provided query when executed

Throws:

RecordCoreException - if the planner cannot plan the query

planQuery

@Nonnull
QueryPlanResult planQuery(@Nonnull
                          RecordQuery query)

Create a plan to get the results of the provided query. This method returns a QueryPlanResult that contains the same plan as returned by plan(RecordQuery) with additional information provided in the QueryPlanInfo

Parameters:

query - a query for records on this planner's metadata

Returns:

a QueryPlanResult that contains the plan for the query with additional information

Throws:

RecordCoreException - if the planner cannot plan the query

getRecordMetaData

@Nonnull
RecordMetaData getRecordMetaData()

Get the RecordMetaData for this planner.

Returns:

the meta-data

getRecordStoreState

@Nonnull
RecordStoreState getRecordStoreState()

Get the RecordStoreState for this planner.

Returns:

the record store state

setIndexScanPreference

void setIndexScanPreference(@Nonnull
                            QueryPlanner.IndexScanPreference indexScanPreference)

Set whether RecordQueryIndexPlan is preferred over RecordQueryScanPlan even when it does not satisfy any additional conditions. Scanning without an index is more efficient, but will have to skip over unrelated record types. For that reason, it is safer to use an index, except when there is only one record type. If the meta-data has more than one record type but the record store does not, this can be overridden.

Parameters:

indexScanPreference - whether to prefer index scan over record scan