public class JoinUtil extends Object
Utility methods for query planning related to joins.
In some cases, a query plan can be made more optimal via a few possible criteria/join optimizations.
Modifier and Type | Method and Description |
---|---|
static JoinType |
getJoinTypePreventingCriteriaOptimization(PlanNode joinNode,
Set<GroupSymbol> groups) |
static boolean |
isNullDependent(QueryMetadataInterface metadata,
Collection<GroupSymbol> innerGroups,
Criteria crit)
Returns true if the given criteria can be anything other than false (or unknown)
given all null values for elements in the inner groups
|
static boolean |
isNullDependent(QueryMetadataInterface metadata,
Collection<GroupSymbol> innerGroups,
Expression expr) |
public static boolean isNullDependent(QueryMetadataInterface metadata, Collection<GroupSymbol> innerGroups, Criteria crit)
public static boolean isNullDependent(QueryMetadataInterface metadata, Collection<GroupSymbol> innerGroups, Expression expr)
public static JoinType getJoinTypePreventingCriteriaOptimization(PlanNode joinNode, Set<GroupSymbol> groups)
Copyright © 2019. All rights reserved.