org.apache.tajo.plan.expr

Class EvalTreeUtil

java.lang.Object

org.apache.tajo.plan.expr.EvalTreeUtil

public class EvalTreeUtil
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	EvalTreeUtil.AllAggFunctionFinder
static class	EvalTreeUtil.AllColumnRefFinder
static class	EvalTreeUtil.AllWindowFunctionFinder
static class	EvalTreeUtil.ChangeColumnRefVisitor
static class	EvalTreeUtil.EvalFinder
static class	EvalTreeUtil.EvalReplaceVisitor
static class	EvalTreeUtil.OuterJoinSensitiveEvalFinder
static class	EvalTreeUtil.UniqueColumnFinder
static class	EvalTreeUtil.VariableCounter

Constructor Summary

Constructors

Constructor and Description
EvalTreeUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static void	changeColumnRef(EvalNode node, String oldName, String newName)
static boolean	checkIfCanBeConstant(EvalNode evalNode)
static String	columnsToStr(Collection<Column> columns)
static boolean	containColumnRef(EvalNode expr, Column target) Examine if the expr contains the column reference corresponding to the target column
static Datum	evaluateImmediately(EvalNode evalNode)
static List<Column>	findAllColumnRefs(EvalNode node)
static Set<AggregationFunctionCallEval>	findDistinctAggFunction(EvalNode expr)
static <T extends EvalNode> Collection<T>	findEvalsByType(EvalNode evalNode, EvalType type)
static <T extends EvalNode> Collection<T>	findOuterJoinSensitiveEvals(EvalNode evalNode)
static LinkedHashSet<Column>	findUniqueColumns(EvalNode node) It finds unique columns from a EvalNode.
static Set<WindowFunctionEval>	findWindowFunction(EvalNode expr)
static Collection<EvalNode>	getContainExpr(EvalNode expr, Column target) Return all exprs to refer columns corresponding to the target.
static TajoDataTypes.DataType	getDomainByExpr(Schema inputSchema, EvalNode expr)
static Map<EvalType,Integer>	getExprCounters(EvalNode expr) Return the counter to count the number of expression types individually.
static Schema	getSchemaByTargets(Schema inputSchema, Target[] targets)
static boolean	isJoinQual(EvalNode expr, boolean includeThetaJoin) If a given expression is join condition, it returns TRUE.
static boolean	isJoinQual(LogicalPlan.QueryBlock block, Schema leftSchema, Schema rightSchema, EvalNode expr, boolean includeThetaJoin) If a given expression is join condition, it returns TRUE.
static int	replace(EvalNode expr, EvalNode targetExpr, EvalNode tobeReplaced)

Methods inherited from class java.lang.Object

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

Constructor Detail

EvalTreeUtil

public EvalTreeUtil()

Method Detail

changeColumnRef

public static void changeColumnRef(EvalNode node,
                   String oldName,
                   String newName)

replace

public static int replace(EvalNode expr,
          EvalNode targetExpr,
          EvalNode tobeReplaced)

findUniqueColumns

public static LinkedHashSet<Column> findUniqueColumns(EvalNode node)

It finds unique columns from a EvalNode.

findAllColumnRefs

public static List<Column> findAllColumnRefs(EvalNode node)

getSchemaByTargets

public static Schema getSchemaByTargets(Schema inputSchema,
                        Target[] targets)
                                 throws InternalException

Throws:

InternalException

columnsToStr

public static String columnsToStr(Collection<Column> columns)

getDomainByExpr

public static TajoDataTypes.DataType getDomainByExpr(Schema inputSchema,
                                     EvalNode expr)
                                              throws InternalException

Throws:

InternalException

getContainExpr

public static Collection<EvalNode> getContainExpr(EvalNode expr,
                                  Column target)

Return all exprs to refer columns corresponding to the target.

Parameters:

expr -

target - to be found

Returns:

a list of exprs

getExprCounters

public static Map<EvalType,Integer> getExprCounters(EvalNode expr)

Return the counter to count the number of expression types individually.

Parameters:

expr -

Returns:

containColumnRef

public static boolean containColumnRef(EvalNode expr,
                       Column target)

Examine if the expr contains the column reference corresponding to the target column

isJoinQual

public static boolean isJoinQual(EvalNode expr,
                 boolean includeThetaJoin)

If a given expression is join condition, it returns TRUE. Otherwise, it returns FALSE. If three conditions are satisfied, we can recognize the expression as a equi join condition.

1. An expression is an equal comparison expression.
2. Both terms in an expression are column references.
3. Both column references point come from different tables

For theta join condition, we will use "an expression is a predicate including column references which come from different two tables" instead of the first rule.

Parameters:

expr - EvalNode to be evaluated

includeThetaJoin - If true, it will return equi as well as non-equi join conditions. Otherwise, it only returns equi-join conditions.

Returns:

True if it is join condition.

isJoinQual

public static boolean isJoinQual(@Nullable
                 LogicalPlan.QueryBlock block,
                 @Nullable
                 Schema leftSchema,
                 @Nullable
                 Schema rightSchema,
                 EvalNode expr,
                 boolean includeThetaJoin)

If a given expression is join condition, it returns TRUE. Otherwise, it returns FALSE. If three conditions are satisfied, we can recognize the expression as a equi join condition.

1. An expression is an equal comparison expression.
2. Both terms in an expression are column references.
3. Both column references point come from different tables

For theta join condition, we will use "an expression is a predicate including column references which come from different two tables" instead of the first rule.

Parameters:

block - if block is not null, it tracks the lineage of aliased name derived from complex expressions.

leftSchema - Schema to be used to check if columns belong to different relations

rightSchema - Schema to be used to check if columns belong to different relations

expr - EvalNode to be evaluated

includeThetaJoin - If true, it will return equi as well as non-equi join conditions. Otherwise, it only returns equi-join conditions.

Returns:

True if it is join condition.

findDistinctAggFunction

public static Set<AggregationFunctionCallEval> findDistinctAggFunction(EvalNode expr)

findWindowFunction

public static Set<WindowFunctionEval> findWindowFunction(EvalNode expr)

findEvalsByType

public static <T extends EvalNode> Collection<T> findEvalsByType(EvalNode evalNode,
                                                 EvalType type)

findOuterJoinSensitiveEvals

public static <T extends EvalNode> Collection<T> findOuterJoinSensitiveEvals(EvalNode evalNode)

checkIfCanBeConstant

public static boolean checkIfCanBeConstant(EvalNode evalNode)

evaluateImmediately

public static Datum evaluateImmediately(EvalNode evalNode)