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*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
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* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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package org.teiid.query.optimizer.relational.rules;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import org.teiid.api.exception.query.QueryMetadataException;
import org.teiid.api.exception.query.QueryPlannerException;
import org.teiid.core.TeiidComponentException;
import org.teiid.core.util.Assertion;
import org.teiid.query.analysis.AnalysisRecord;
import org.teiid.query.metadata.QueryMetadataInterface;
import org.teiid.query.optimizer.capabilities.CapabilitiesFinder;
import org.teiid.query.optimizer.relational.OptimizerRule;
import org.teiid.query.optimizer.relational.RuleStack;
import org.teiid.query.optimizer.relational.plantree.NodeConstants;
import org.teiid.query.optimizer.relational.plantree.NodeEditor;
import org.teiid.query.optimizer.relational.plantree.NodeFactory;
import org.teiid.query.optimizer.relational.plantree.PlanNode;
import org.teiid.query.sql.lang.JoinType;
import org.teiid.query.sql.lang.OrderBy;
import org.teiid.query.sql.lang.OrderByItem;
import org.teiid.query.sql.lang.SetQuery;
import org.teiid.query.sql.symbol.AliasSymbol;
import org.teiid.query.sql.symbol.ExpressionSymbol;
import org.teiid.query.sql.symbol.GroupSymbol;
import org.teiid.query.sql.symbol.SingleElementSymbol;
import org.teiid.query.sql.util.SymbolMap;
import org.teiid.query.util.CommandContext;
/**
* Will attempt to raise null nodes to their highest points
*/
public final class RuleRaiseNull implements OptimizerRule {
public PlanNode execute(PlanNode plan, QueryMetadataInterface metadata, CapabilitiesFinder capFinder, RuleStack rules, AnalysisRecord analysisRecord, CommandContext context)
throws QueryPlannerException, QueryMetadataException, TeiidComponentException {
List<PlanNode> nodes = NodeEditor.findAllNodes(plan, NodeConstants.Types.NULL);
//create a new list to iterate over since the original will be modified
for (PlanNode nullNode : new LinkedList<PlanNode>(nodes)) {
while (nullNode.getParent() != null && nodes.contains(nullNode)) {
// Attempt to raise the node
PlanNode newRoot = raiseNullNode(plan, nodes, nullNode, metadata, capFinder);
if(newRoot != null) {
plan = newRoot;
} else {
break;
}
}
if (nullNode.getParent() == null) {
nodes.remove(nullNode);
}
}
return plan;
}
/**
* @param nullNode
* @param metadata
* @param capFinder
* @return null if the raising should not continue, else the newRoot
*/
PlanNode raiseNullNode(PlanNode rootNode, List<PlanNode> nodes, PlanNode nullNode, QueryMetadataInterface metadata, CapabilitiesFinder capFinder)
throws QueryPlannerException, QueryMetadataException, TeiidComponentException {
PlanNode parentNode = nullNode.getParent();
switch(parentNode.getType()) {
case NodeConstants.Types.JOIN:
{
JoinType jt = (JoinType)parentNode.getProperty(NodeConstants.Info.JOIN_TYPE);
if (jt == JoinType.JOIN_CROSS || jt == JoinType.JOIN_INNER) {
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
//for outer joins if the null node is on the outer side, then the join itself is null
//if the null node is on the inner side, then the join can be removed but the null values
//coming from the inner side will need to be placed into the frame
if (jt == JoinType.JOIN_LEFT_OUTER) {
if (nullNode == parentNode.getFirstChild()) {
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
raiseNullThroughJoin(metadata, parentNode, parentNode.getLastChild());
return null;
}
if (jt == JoinType.JOIN_RIGHT_OUTER) {
if (nullNode == parentNode.getLastChild()) {
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
raiseNullThroughJoin(metadata, parentNode, parentNode.getFirstChild());
return null;
}
if (jt == JoinType.JOIN_FULL_OUTER) {
if (nullNode == parentNode.getLastChild()) {
raiseNullThroughJoin(metadata, parentNode, parentNode.getLastChild());
} else {
raiseNullThroughJoin(metadata, parentNode, parentNode.getFirstChild());
}
return null;
}
break;
}
case NodeConstants.Types.SET_OP:
{
boolean isLeftChild = parentNode.getFirstChild() == nullNode;
SetQuery.Operation operation = (SetQuery.Operation)parentNode.getProperty(NodeConstants.Info.SET_OPERATION);
boolean raiseOverSetOp = (operation == SetQuery.Operation.INTERSECT || (operation == SetQuery.Operation.EXCEPT && isLeftChild));
if (raiseOverSetOp) {
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
boolean isAll = parentNode.hasBooleanProperty(NodeConstants.Info.USE_ALL);
if (isLeftChild) {
PlanNode firstProject = NodeEditor.findNodePreOrder(parentNode, NodeConstants.Types.PROJECT);
if (firstProject == null) { // will only happen if the other branch has only null nodes
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
List<SingleElementSymbol> newProjectSymbols = (List<SingleElementSymbol>)firstProject.getProperty(NodeConstants.Info.PROJECT_COLS);
List<SingleElementSymbol> oldProjectSymbols = (List<SingleElementSymbol>)nullNode.getProperty(NodeConstants.Info.PROJECT_COLS);
for (int i = 0; i < newProjectSymbols.size(); i++) {
SingleElementSymbol newSes = newProjectSymbols.get(i);
SingleElementSymbol oldSes = oldProjectSymbols.get(i);
if (newSes instanceof ExpressionSymbol || !newSes.getShortCanonicalName().equals(oldSes.getShortCanonicalName())) {
if (newSes instanceof AliasSymbol) {
newSes = ((AliasSymbol)newSes).getSymbol();
}
newProjectSymbols.set(i, new AliasSymbol(oldSes.getShortName(), newSes));
}
}
PlanNode sort = NodeEditor.findParent(firstProject, NodeConstants.Types.SORT, NodeConstants.Types.SOURCE);
if (sort != null) { //correct the sort to the new columns as well
OrderBy sortOrder = (OrderBy)sort.getProperty(NodeConstants.Info.SORT_ORDER);
for (OrderByItem item : sortOrder.getOrderByItems()) {
SingleElementSymbol sortElement = item.getSymbol();
sortElement = newProjectSymbols.get(oldProjectSymbols.indexOf(sortElement));
item.setSymbol(sortElement);
}
}
PlanNode sourceNode = NodeEditor.findParent(parentNode, NodeConstants.Types.SOURCE);
if (sourceNode != null && NodeEditor.findNodePreOrder(sourceNode, NodeConstants.Types.PROJECT) == firstProject) {
SymbolMap symbolMap = (SymbolMap)sourceNode.getProperty(NodeConstants.Info.SYMBOL_MAP);
symbolMap = SymbolMap.createSymbolMap(symbolMap.getKeys(), newProjectSymbols);
sourceNode.setProperty(NodeConstants.Info.SYMBOL_MAP, symbolMap);
}
}
NodeEditor.removeChildNode(parentNode, nullNode);
PlanNode grandParent = parentNode.getParent();
if (!isAll) { //ensure that the new child is distinct
PlanNode nestedSetOp = NodeEditor.findNodePreOrder(parentNode.getFirstChild(), NodeConstants.Types.SET_OP, NodeConstants.Types.SOURCE);
if (nestedSetOp != null) {
nestedSetOp.setProperty(NodeConstants.Info.USE_ALL, false);
} else if (NodeEditor.findNodePreOrder(parentNode.getFirstChild(), NodeConstants.Types.DUP_REMOVE, NodeConstants.Types.SOURCE) == null) {
parentNode.getFirstChild().addAsParent(NodeFactory.getNewNode(NodeConstants.Types.DUP_REMOVE));
}
}
if (grandParent == null) {
PlanNode newRoot = parentNode.getFirstChild();
parentNode.removeChild(newRoot);
return newRoot;
}
//remove the set op
NodeEditor.removeChildNode(grandParent, parentNode);
PlanNode sourceNode = NodeEditor.findParent(grandParent.getFirstChild(), NodeConstants.Types.SOURCE, NodeConstants.Types.SET_OP);
if (sourceNode != null) {
return RuleMergeVirtual.doMerge(sourceNode, rootNode, false, metadata);
}
return null;
}
case NodeConstants.Types.GROUP:
{
//if there are grouping columns, then we can raise
if (parentNode.hasCollectionProperty(NodeConstants.Info.GROUP_COLS)) {
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
break; //- the else case could be implemented, but it's a lot of work for little gain, since the null node can't raise higher
}
case NodeConstants.Types.PROJECT:
{
// check for project into
PlanNode upperProject = NodeEditor.findParent(parentNode.getParent(), NodeConstants.Types.PROJECT);
if (upperProject == null
|| upperProject.getProperty(NodeConstants.Info.INTO_GROUP) == null) {
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
break;
}
default:
{
return raiseNullNode(rootNode, parentNode, nullNode, nodes);
}
}
return null;
}
private PlanNode raiseNullNode(PlanNode rootNode, PlanNode parentNode, PlanNode nullNode, List<PlanNode> nodes) {
if (parentNode.getType() == NodeConstants.Types.SOURCE) {
nullNode.getGroups().clear();
} else if (parentNode.getType() == NodeConstants.Types.PROJECT) {
nullNode.setProperty(NodeConstants.Info.PROJECT_COLS, parentNode.getProperty(NodeConstants.Info.PROJECT_COLS));
}
nullNode.addGroups(parentNode.getGroups());
parentNode.removeChild(nullNode);
nodes.removeAll(NodeEditor.findAllNodes(parentNode, NodeConstants.Types.NULL));
if (parentNode.getParent() != null) {
parentNode.getParent().replaceChild(parentNode, nullNode);
} else {
rootNode = nullNode;
}
return rootNode;
}
/**
* Given a joinNode that should be an outer join and a null node as one of its children, replace elements in
* the current frame from the null node groups with null values
*
* @param metadata
* @param joinNode
* @param nullNode
* @throws QueryPlannerException
* @throws QueryMetadataException
* @throws TeiidComponentException
*/
static void raiseNullThroughJoin(QueryMetadataInterface metadata,
PlanNode joinNode,
PlanNode nullNode) throws QueryPlannerException,
QueryMetadataException,
TeiidComponentException {
Assertion.assertTrue(joinNode.getType() == NodeConstants.Types.JOIN);
Assertion.assertTrue(nullNode.getType() == NodeConstants.Types.NULL);
Assertion.assertTrue(nullNode.getParent() == joinNode);
PlanNode frameStart = joinNode.getParent();
NodeEditor.removeChildNode(joinNode, nullNode);
NodeEditor.removeChildNode(joinNode.getParent(), joinNode);
for (GroupSymbol group : nullNode.getGroups()) {
Map nullSymbolMap = FrameUtil.buildSymbolMap(group, null, metadata);
FrameUtil.convertFrame(frameStart, group, null, nullSymbolMap, metadata);
}
}
public String toString() {
return "RaiseNull"; //$NON-NLS-1$
}
}