Package org.apache.druid.sql.calcite.rule

Class ReverseLookupRule

java.lang.Object

org.apache.calcite.plan.RelOptRule

org.apache.druid.sql.calcite.rule.ReverseLookupRule

All Implemented Interfaces:

org.apache.calcite.rel.rules.SubstitutionRule, org.apache.calcite.rel.rules.TransformationRule

public class ReverseLookupRule
extends org.apache.calcite.plan.RelOptRule
implements org.apache.calcite.rel.rules.SubstitutionRule

Eliminates calls to QueryLookupOperatorConversion.SQL_FUNCTION by doing reverse-lookups. Considers reversing SqlStdOperatorTable.IS_NULL and operators that match isBinaryComparison(RexNode). However, reversal is not done in all cases, such as when it would require embedding the entire lookup into the query, or when the number of keys exceeds QueryContext.getInSubQueryThreshold(). The heart of the class, where the reversal actually happens, is ReverseLookupRule.ReverseLookupShuttle.CollectReverseLookups.reverseLookup(org.apache.druid.query.lookup.LookupExtractor, java.lang.String, org.apache.druid.query.filter.InDimFilter.ValuesSet, boolean). The rest of the rule is mainly about grouping together as many LOOKUP calls as possible prior to attempting to reverse, since reversing a lookup may require iteration of the lookup. We don't want to do that more often than necessary.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.calcite.plan.RelOptRule

org.apache.calcite.plan.RelOptRule.ConverterRelOptRuleOperand

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CTX_MAX_OPTIMIZE_COUNT	Context parameter for tests, to allow us to confirm that this rule doesn't do too many calls to InDimFilter.optimize(boolean).
static final String	CTX_THRESHOLD	Context parameter to prevent creating too-large IN filters as a result of reverse lookups.
static final int	DEFAULT_THRESHOLD	Context parameter for tests, to allow us to force the case where we avoid creating a bunch of ORs.

Fields inherited from class org.apache.calcite.plan.RelOptRule

description, operands, relBuilderFactory

Constructor Summary

Constructors

Constructor	Description
ReverseLookupRule(PlannerContext plannerContext)

Method Summary

Modifier and Type	Method	Description
void	onMatch(org.apache.calcite.plan.RelOptRuleCall call)

Methods inherited from class org.apache.calcite.plan.RelOptRule

any, convert, convert, convert, convert, convertList, convertOperand, convertOperand, equals, equals, getOperand, getOperands, getOutConvention, getOutTrait, hashCode, matches, none, operand, operand, operand, operand, operand, operandJ, operandJ, some, toString, unordered

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.calcite.rel.rules.SubstitutionRule

autoPruneOld

Field Details

CTX_MAX_OPTIMIZE_COUNT

public static final String CTX_MAX_OPTIMIZE_COUNT

Context parameter for tests, to allow us to confirm that this rule doesn't do too many calls to InDimFilter.optimize(boolean). This is important because certain lookup implementations, most prominently MapLookupExtractor, do a full iteration of the map for each call to LookupExtractor.unapplyAll(java.util.Set<java.lang.String>), which may be called by InDimFilter.optimize(boolean).

See Also:

• Constant Field Values

CTX_THRESHOLD

public static final String CTX_THRESHOLD

Context parameter to prevent creating too-large IN filters as a result of reverse lookups.

See Also:

• Constant Field Values

DEFAULT_THRESHOLD

public static final int DEFAULT_THRESHOLD

Context parameter for tests, to allow us to force the case where we avoid creating a bunch of ORs.

See Also:

• Constant Field Values

Constructor Details

ReverseLookupRule

public ReverseLookupRule(PlannerContext plannerContext)

Method Details

onMatch

public void onMatch(org.apache.calcite.plan.RelOptRuleCall call)

Specified by:

onMatch in class org.apache.calcite.plan.RelOptRule