org.apache.drill.exec.planner.common

Class DrillRelOptUtil

java.lang.Object

org.apache.drill.exec.planner.common.DrillRelOptUtil

public abstract class DrillRelOptUtil
extends Object

Utility class that is a subset of the RelOptUtil class and is a placeholder for Drill specific static methods that are needed during either logical or physical planning.

Constructor Summary

Constructors

Constructor and Description
DrillRelOptUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	areRowTypesCompatible(org.apache.calcite.rel.type.RelDataType rowType1, org.apache.calcite.rel.type.RelDataType rowType2, boolean compareNames, boolean allowSubstring)
static org.apache.calcite.rel.RelNode	createRename(org.apache.calcite.rel.RelNode rel, List<String> fieldNames) Returns a relational expression which has the same fields as the underlying expression, but the fields have different names.
static org.apache.calcite.rex.RexCall	findItemOrFlatten(org.apache.calcite.rex.RexNode node, List<org.apache.calcite.rex.RexNode> projExprs) Travesal RexNode to find the item/flattern operator.
static boolean	isTrivialProject(org.apache.calcite.rel.core.Project project, boolean useNamesInIdentityProjCalc)
static org.apache.calcite.rel.type.RelDataType	uniqifyFieldName(org.apache.calcite.rel.type.RelDataType rowType, org.apache.calcite.rel.type.RelDataTypeFactory typeFactory) Returns a rowType having all unique field name.

Methods inherited from class java.lang.Object

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

Constructor Detail

DrillRelOptUtil

public DrillRelOptUtil()

Method Detail

areRowTypesCompatible

public static boolean areRowTypesCompatible(org.apache.calcite.rel.type.RelDataType rowType1,
                            org.apache.calcite.rel.type.RelDataType rowType2,
                            boolean compareNames,
                            boolean allowSubstring)

createRename

public static org.apache.calcite.rel.RelNode createRename(org.apache.calcite.rel.RelNode rel,
                                          List<String> fieldNames)

Returns a relational expression which has the same fields as the underlying expression, but the fields have different names.

Parameters:

rel - Relational expression

fieldNames - Field names

Returns:

Renamed relational expression

isTrivialProject

public static boolean isTrivialProject(org.apache.calcite.rel.core.Project project,
                       boolean useNamesInIdentityProjCalc)

uniqifyFieldName

public static org.apache.calcite.rel.type.RelDataType uniqifyFieldName(org.apache.calcite.rel.type.RelDataType rowType,
                                                       org.apache.calcite.rel.type.RelDataTypeFactory typeFactory)

Returns a rowType having all unique field name.

Parameters:

rowType - : input rowType

typeFactory - : type factory used to create a new row type.

Returns:

findItemOrFlatten

public static org.apache.calcite.rex.RexCall findItemOrFlatten(org.apache.calcite.rex.RexNode node,
                                               List<org.apache.calcite.rex.RexNode> projExprs)

Travesal RexNode to find the item/flattern operator. Continue search if RexNode has a RexInputRef which refers to a RexNode in project expressions.

Parameters:

node - : RexNode to search

projExprs - : the list of project expressions. Empty list means there is No project operator underneath.

Returns:

: Return null if there is NONE; return the first appearance of item/flatten RexCall.