com.apple.foundationdb.record.query.plan

Interface QueryPlanner

All Known Implementing Classes:

CascadesPlanner, RecordQueryPlanner

@API(value=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 and Description
static class	QueryPlanner.IndexScanPreference Preference between index scan and record scan.

Method Summary

Modifier and Type	Method and Description
RecordQueryPlan	plan(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

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