com.apple.foundationdb.record.query.plan.temp.rules

Class SortToIndexRule

java.lang.Object

com.apple.foundationdb.record.query.plan.temp.PlannerRule<LogicalSortExpression>

com.apple.foundationdb.record.query.plan.temp.rules.SortToIndexRule

@API(value=EXPERIMENTAL)
public class SortToIndexRule
extends PlannerRule<LogicalSortExpression>

A rule for implementing a LogicalSortExpression as a scan of an appropriately-ordered index. There are a few things to note about how this rule currently works:

• It relies on KeyExpression.isPrefixKey(KeyExpression) to do the "heavy lifting" of determining whether or not a sort can be implemented using an index, which currently involves calling ExpressionRef.get(). This obviously does not work if the ExpressionRef is not gettable (for example, if it were a group).
• It will plan the sort using the first index with an appropriate ordering.

Ths first of these details will definitely change as the planner improves.

Constructor Summary

Constructors

Constructor and Description
SortToIndexRule()

Method Summary

Modifier and Type	Method and Description
void	onMatch(PlannerRuleCall call)

Methods inherited from class com.apple.foundationdb.record.query.plan.temp.PlannerRule

getMatcher, getRootOperator, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

SortToIndexRule

public SortToIndexRule()

Method Detail

onMatch

public void onMatch(@Nonnull
                    PlannerRuleCall call)

Specified by:

onMatch in class PlannerRule<LogicalSortExpression>