org.eigenbase.sql2rel
Class SqlToRelConverter.Blackboard

java.lang.Object
  org.eigenbase.sql2rel.SqlToRelConverter.Blackboard

All Implemented Interfaces:

SqlVisitor<RexNode>, SqlRexContext

Enclosing class:

SqlToRelConverter

protected class SqlToRelConverter.Blackboard
extends Object
implements SqlRexContext, SqlVisitor<RexNode>

Workspace for translating an individual SELECT statement (or sub-SELECT).

Field Summary

(package private) SqlToRelConverter.AggConverter	agg Workspace for building aggregates.
private List<SqlMonotonicity>	columnMonotonicities
(package private) List<RelNode>	cursors
private RelNode[]	inputs
private Map<String,RexNode>	mapCorrelateVariableToRexNode
private Map<RelNode,Map<Integer,Integer>>	mapRootRelToFieldProjection Project the groupby expressions out of the root of this sub-select.
private Map<SqlNode,RexNode>	mapSubqueryToExpr Maps IN and EXISTS sub-queries to the expressions which will be used to access them.
private Map<String,RexNode>	nameToNodeMap
RelNode	root
SqlValidatorScope	scope Collection of RelNode objects which correspond to a SELECT statement.
private List<SqlNode>	subqueryList List of IN and EXISTS nodes inside this SELECT statement (but not inside sub-queries).
private boolean	subqueryNeedsOuterJoin
private List<RelDataTypeField>	systemFieldList

Constructor Summary

protected

SqlToRelConverter.Blackboard(SqlValidatorScope scope, Map<String,RexNode> nameToNodeMap) Creates a Blackboard.

Method Summary

void	adjustSubqueries(int index, int count) Shifts the expressions used to reference subqueries to the right.
RexNode	convertExpression(SqlNode expr) Converts an expression from SqlNode to RexNode format.
RexNode	convertInterval(SqlIntervalQualifier intervalQualifier)
RexNode	convertLiteral(SqlLiteral literal) Converts a literal.
void	flatten(RelNode[] rels, int systemFieldCount, int[] start, List<Pair<RelNode,Integer>> relOffsetList)
List<SqlMonotonicity>	getColumnMonotonicities()
DefaultValueFactory	getDefaultValueFactory() Returns the factory which supplies default values for INSERT, UPDATE, and NEW.
RexBuilder	getRexBuilder() Returns the RexBuilder to use to create RexNode objects.
(package private) RelDataTypeField	getRootField(RexInputRef inputRef)
RexRangeRef	getSubqueryExpr(SqlCall call) Returns the expression used to access a given IN or EXISTS sub-query.
RelDataTypeFactory	getTypeFactory() Returns the type factory.
SqlValidator	getValidator() Returns the validator.
private boolean	isConvertedSubq(RexNode rex) Determines whether a RexNode corresponds to a subquery that's been converted to a constant.
(package private) RexNode	lookup(int offset, SqlToRelConverter.LookupContext lookupContext) Creates an expression with which to reference the expression whose offset in its from-list is offset.
(package private) RexNode	lookupExp(String name) Returns an expression with which to reference a from-list item.
RexNode	register(RelNode rel, JoinRelType joinType)
RexNode	register(RelNode rel, JoinRelType joinType, RexNode[] leftJoinKeysForIn) Registers a relational expression.
(package private) void	registerSubquery(SqlNode node)
(package private) RelNode[]	retrieveCursors()
void	setDataset(String datasetName) Notifies this Blackboard that the root just set using setRoot(RelNode, boolean) was derived using dataset substitution.
(package private) void	setRoot(RelNode[] inputs)
private void	setRoot(RelNode[] inputs, RelNode root, boolean hasSystemFields)
void	setRoot(RelNode root, boolean leaf) Sets a new root relational expression, as the translation process backs its way further up the tree.
RexNode	visit(SqlCall call) Visits a call to a SqlOperator.
RexNode	visit(SqlDataTypeSpec type) Visits a datatype specification.
RexNode	visit(SqlDynamicParam param) Visits a dynamic parameter.
RexNode	visit(SqlIdentifier id) Visits an identifier.
RexNode	visit(SqlIntervalQualifier intervalQualifier) Visits an interval qualifier
RexNode	visit(SqlLiteral literal) Visits a literal.
RexNode	visit(SqlNodeList nodeList) Visits a list of SqlNode objects.

Methods inherited from class java.lang.Object

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

Field Detail

scope

public final SqlValidatorScope scope

Collection of RelNode objects which correspond to a SELECT statement.

nameToNodeMap

private final Map<String,RexNode> nameToNodeMap

root

public RelNode root

inputs

private RelNode[] inputs

mapCorrelateVariableToRexNode

private final Map<String,RexNode> mapCorrelateVariableToRexNode

cursors

List<RelNode> cursors

subqueryList

private final List<SqlNode> subqueryList

List of IN and EXISTS nodes inside this SELECT statement (but not inside sub-queries).

mapSubqueryToExpr

private final Map<SqlNode,RexNode> mapSubqueryToExpr

Maps IN and EXISTS sub-queries to the expressions which will be used to access them.

subqueryNeedsOuterJoin

private boolean subqueryNeedsOuterJoin

agg

SqlToRelConverter.AggConverter agg

Workspace for building aggregates.

mapRootRelToFieldProjection

private final Map<RelNode,Map<Integer,Integer>> mapRootRelToFieldProjection

Project the groupby expressions out of the root of this sub-select. Subqueries can reference group by expressions projected from the "right" to the subquery.

columnMonotonicities

private final List<SqlMonotonicity> columnMonotonicities

systemFieldList

private final List<RelDataTypeField> systemFieldList

Constructor Detail

SqlToRelConverter.Blackboard

protected SqlToRelConverter.Blackboard(SqlValidatorScope scope,
                                       Map<String,RexNode> nameToNodeMap)

Creates a Blackboard.

Parameters:

scope - Name-resolution scope for expressions validated within this query. Can be null if this Blackboard is for a leaf node, say

nameToNodeMap - Map which translates the expression to map a given parameter into, if translating expressions; null otherwise

Method Detail

register

public RexNode register(RelNode rel,
                        JoinRelType joinType)

register

public RexNode register(RelNode rel,
                        JoinRelType joinType,
                        RexNode[] leftJoinKeysForIn)

Registers a relational expression.

Parameters:

rel - Relational expression

joinType - Join type

leftJoinKeysForIn - LHS of IN clause, or null for expressions other than IN

Returns:

Expression with which to refer to the row (or partial row) coming from this relational expression's side of the join. rchen 2006-08-17: temporarily translate select * from X where a not in (select b form Y); to select X.* from X, (select distinct b from Y) where not (a = b);

setRoot

public void setRoot(RelNode root,
                    boolean leaf)

Sets a new root relational expression, as the translation process backs its way further up the tree.

Parameters:

root - New root relational expression

leaf - Whether the relational expression is a leaf, that is, derived from an atomic relational expression such as a table name in the from clause, or the projection on top of a select-subquery. In particular, relational expressions derived from JOIN operators are not leaves, but set expressions are.

setRoot

private void setRoot(RelNode[] inputs,
                     RelNode root,
                     boolean hasSystemFields)

setDataset

public void setDataset(String datasetName)

Notifies this Blackboard that the root just set using setRoot(RelNode, boolean) was derived using dataset substitution.

The default implementation is not interested in such notifications, and does nothing.

Parameters:

datasetName - Dataset name

setRoot

void setRoot(RelNode[] inputs)

lookupExp

RexNode lookupExp(String name)

Returns an expression with which to reference a from-list item.

Parameters:

name - the alias of the from item

Returns:

a RexFieldAccess or RexRangeRef, or null if not found

lookup

RexNode lookup(int offset,
               SqlToRelConverter.LookupContext lookupContext)

Creates an expression with which to reference the expression whose offset in its from-list is offset.

getRootField

RelDataTypeField getRootField(RexInputRef inputRef)

flatten

public void flatten(RelNode[] rels,
                    int systemFieldCount,
                    int[] start,
                    List<Pair<RelNode,Integer>> relOffsetList)

registerSubquery

void registerSubquery(SqlNode node)

retrieveCursors

RelNode[] retrieveCursors()

convertExpression

public RexNode convertExpression(SqlNode expr)

Description copied from interface: SqlRexContext

Converts an expression from SqlNode to RexNode format.

Specified by:

convertExpression in interface SqlRexContext

Parameters:

expr - Expression to translate

Returns:

Converted expression

isConvertedSubq

private boolean isConvertedSubq(RexNode rex)

Determines whether a RexNode corresponds to a subquery that's been converted to a constant.

Parameters:

rex - the expression to be examined

Returns:

true if the expression is a dynamic parameter, a literal, or a literal that is being cast

getRexBuilder

public RexBuilder getRexBuilder()

Description copied from interface: SqlRexContext

Returns the RexBuilder to use to create RexNode objects.

Specified by:

getRexBuilder in interface SqlRexContext

getSubqueryExpr

public RexRangeRef getSubqueryExpr(SqlCall call)

Description copied from interface: SqlRexContext

Returns the expression used to access a given IN or EXISTS sub-query.

Specified by:

getSubqueryExpr in interface SqlRexContext

Parameters:

call - IN or EXISTS expression

Returns:

Expression used to access current row of sub-query

getTypeFactory

public RelDataTypeFactory getTypeFactory()

Description copied from interface: SqlRexContext

Returns the type factory.

Specified by:

getTypeFactory in interface SqlRexContext

getDefaultValueFactory

public DefaultValueFactory getDefaultValueFactory()

Description copied from interface: SqlRexContext

Returns the factory which supplies default values for INSERT, UPDATE, and NEW.

Specified by:

getDefaultValueFactory in interface SqlRexContext

getValidator

public SqlValidator getValidator()

Description copied from interface: SqlRexContext

Returns the validator.

Specified by:

getValidator in interface SqlRexContext

convertLiteral

public RexNode convertLiteral(SqlLiteral literal)

Description copied from interface: SqlRexContext

Converts a literal.

Specified by:

convertLiteral in interface SqlRexContext

convertInterval

public RexNode convertInterval(SqlIntervalQualifier intervalQualifier)

visit

public RexNode visit(SqlLiteral literal)

Description copied from interface: SqlVisitor

Visits a literal.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

literal - Literal

See Also:

SqlLiteral.accept(SqlVisitor)

visit

public RexNode visit(SqlCall call)

Description copied from interface: SqlVisitor

Visits a call to a SqlOperator.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

call - Call

See Also:

SqlCall.accept(SqlVisitor)

visit

public RexNode visit(SqlNodeList nodeList)

Description copied from interface: SqlVisitor

Visits a list of SqlNode objects.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

nodeList - list of nodes

See Also:

SqlNodeList.accept(SqlVisitor)

visit

public RexNode visit(SqlIdentifier id)

Description copied from interface: SqlVisitor

Visits an identifier.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

id - identifier

See Also:

SqlIdentifier.accept(SqlVisitor)

visit

public RexNode visit(SqlDataTypeSpec type)

Description copied from interface: SqlVisitor

Visits a datatype specification.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

type - datatype specification

See Also:

SqlDataTypeSpec.accept(SqlVisitor)

visit

public RexNode visit(SqlDynamicParam param)

Description copied from interface: SqlVisitor

Visits a dynamic parameter.

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

param - Dynamic parameter

See Also:

SqlDynamicParam.accept(SqlVisitor)

visit

public RexNode visit(SqlIntervalQualifier intervalQualifier)

Description copied from interface: SqlVisitor

Visits an interval qualifier

Specified by:

visit in interface SqlVisitor<RexNode>

Parameters:

intervalQualifier - Interval qualifier

See Also:

SqlIntervalQualifier.accept(SqlVisitor)

adjustSubqueries

public void adjustSubqueries(int index,
                             int count)

Shifts the expressions used to reference subqueries to the right. Moves any reference ≥ index count places to the right.

Parameters:

index - Position where new expression was inserted

count - Number of new expressions inserted

getColumnMonotonicities

public List<SqlMonotonicity> getColumnMonotonicities()