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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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*
* This library is distributed in the hope that it will be useful,
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* 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
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package org.teiid.query.optimizer.relational.rules;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.teiid.api.exception.query.QueryMetadataException;
import org.teiid.api.exception.query.QueryPlannerException;
import org.teiid.core.TeiidComponentException;
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.optimizer.relational.plantree.NodeConstants.Info;
import org.teiid.query.processor.relational.JoinNode.JoinStrategyType;
import org.teiid.query.rewriter.QueryRewriter;
import org.teiid.query.sql.LanguageObject;
import org.teiid.query.sql.lang.Criteria;
import org.teiid.query.sql.lang.JoinType;
import org.teiid.query.sql.lang.Select;
import org.teiid.query.sql.symbol.Constant;
import org.teiid.query.sql.symbol.ElementSymbol;
import org.teiid.query.sql.symbol.Expression;
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;
/**
* Perform the optimization:<pre>
* source
* inner join union all
* source inner join
* union all => source
* a a
* b source
* source c
* union all inner join
* c source
* d b
* source
* d
* </pre>
*
* TODO: non-ansi joins
*/
public class RuleDecomposeJoin implements OptimizerRule {
@Override
public PlanNode execute(PlanNode plan, QueryMetadataInterface metadata,
CapabilitiesFinder capabilitiesFinder, RuleStack rules,
AnalysisRecord analysisRecord, CommandContext context)
throws QueryPlannerException, QueryMetadataException,
TeiidComponentException {
for (PlanNode joinNode : NodeEditor.findAllNodes(plan, NodeConstants.Types.JOIN, NodeConstants.Types.ACCESS)) {
plan = decomposeJoin(joinNode, plan, metadata, context);
}
return plan;
}
public PlanNode decomposeJoin(PlanNode joinNode, PlanNode root, QueryMetadataInterface metadata, CommandContext context) throws TeiidComponentException, QueryPlannerException {
//TODO: should be done based upon join region to allow more than a 2-way non-ansi join
JoinType joinType = (JoinType)joinNode.getProperty(Info.JOIN_TYPE);
if (joinType != JoinType.JOIN_INNER) {
return root;
}
PlanNode left = joinNode.getFirstChild();
if (left.getType() != NodeConstants.Types.SOURCE) {
return root;
}
Map<ElementSymbol, List<Set<Constant>>> partitionInfo = (Map<ElementSymbol, List<Set<Constant>>>)left.getProperty(Info.PARTITION_INFO);
if (partitionInfo == null) {
return root;
}
PlanNode unionNode = left.getFirstChild();
if (unionNode.getType() != NodeConstants.Types.SET_OP) {
return root;
}
PlanNode right = joinNode.getLastChild();
if (right.getType() != NodeConstants.Types.SOURCE) {
return root;
}
Map<ElementSymbol, List<Set<Constant>>> rightPartionInfo = (Map<ElementSymbol, List<Set<Constant>>>)right.getProperty(Info.PARTITION_INFO);
if (rightPartionInfo == null) {
return root;
}
List<Criteria> criteria = (List<Criteria>)joinNode.getProperty(Info.JOIN_CRITERIA);
List<Expression> expr = new ArrayList<Expression>();
List<Expression> exprOther = new ArrayList<Expression>();
RuleChooseJoinStrategy.separateCriteria(unionNode.getParent().getGroups(), right.getGroups(), expr, exprOther, criteria, new LinkedList<Criteria>());
if (expr.isEmpty()) {
return root; //no equi-join
}
List<int[]> matches = findMatches(partitionInfo, rightPartionInfo, expr, exprOther);
if (matches == null) {
return root; //no non-overlapping partitions
}
int branchSize = partitionInfo.values().iterator().next().size();
int otherBranchSize = rightPartionInfo.values().iterator().next().size();
if (matches.isEmpty()) {
//no matches mean that we can just insert a null node (false criteria) and be done with it
PlanNode critNode = NodeFactory.getNewNode(NodeConstants.Types.SELECT);
critNode.setProperty(Info.SELECT_CRITERIA, QueryRewriter.FALSE_CRITERIA);
unionNode.addAsParent(critNode);
return root;
}
List<PlanNode> branches = new ArrayList<PlanNode>();
//TODO: find union children from RulePushAggregates
RulePushSelectCriteria.collectUnionChildren(unionNode, branches);
if (branches.size() != branchSize) {
return root; //sanity check
}
List<PlanNode> otherBranches = new ArrayList<PlanNode>();
RulePushSelectCriteria.collectUnionChildren(right.getFirstChild(), otherBranches);
if (otherBranches.size() != otherBranchSize) {
return root; //sanity check
}
PlanNode newUnion = buildUnion(unionNode, right, criteria, matches, branches, otherBranches);
PlanNode view = rebuild(left.getGroups().iterator().next(), joinNode, newUnion, metadata, context, left, right);
SymbolMap symbolmap = (SymbolMap)view.getProperty(Info.SYMBOL_MAP);
HashMap<ElementSymbol, List<Set<Constant>>> newPartitionInfo = new LinkedHashMap<ElementSymbol, List<Set<Constant>>>();
for (int[] match : matches) {
updatePartitionInfo(partitionInfo, matches, symbolmap, newPartitionInfo, 0, match[0]);
updatePartitionInfo(rightPartionInfo, matches, symbolmap, newPartitionInfo, partitionInfo.size(), match[1]);
}
view.setProperty(Info.PARTITION_INFO, newPartitionInfo);
//since we've created a new union node, there's a chance we can decompose again
return decomposeJoin(newUnion, root, metadata, context);
}
private void updatePartitionInfo(
Map<ElementSymbol, List<Set<Constant>>> partitionInfo,
List<int[]> matches, SymbolMap symbolmap,
HashMap<ElementSymbol, List<Set<Constant>>> newPartitionInfo, int start, int index) {
for (Map.Entry<ElementSymbol, List<Set<Constant>>> entry : partitionInfo.entrySet()) {
ElementSymbol newSymbol = symbolmap.getKeys().get(start++);
List<Set<Constant>> values = newPartitionInfo.get(newSymbol);
if (values == null) {
values = new ArrayList<Set<Constant>>(matches.size());
newPartitionInfo.put(newSymbol, values);
}
values.add(entry.getValue().get(index));
}
}
/**
* Add the new union back in under a view
*/
static PlanNode rebuild(GroupSymbol group, PlanNode toReplace, PlanNode newUnion, QueryMetadataInterface metadata, CommandContext context,
PlanNode... toMap)
throws TeiidComponentException, QueryPlannerException,
QueryMetadataException {
Set<String> groups = context.getGroups();
if (groups == null) {
groups = new HashSet<String>();
context.setGroups(groups);
}
group = RulePlaceAccess.recontextSymbol(group, groups);
PlanNode projectNode = NodeEditor.findNodePreOrder(newUnion, NodeConstants.Types.PROJECT);
List<? extends SingleElementSymbol> projectedSymbols = (List<? extends SingleElementSymbol>)projectNode.getProperty(Info.PROJECT_COLS);
PlanNode view = RulePushAggregates.createView(group, projectedSymbols, newUnion, metadata);
SymbolMap newSymbolMap = (SymbolMap)view.getProperty(Info.SYMBOL_MAP);
Map<Expression, ElementSymbol> inverseMap = newSymbolMap.inserseMapping();
toReplace.getParent().replaceChild(toReplace, view);
Set<GroupSymbol> newGroups = Collections.singleton(group);
for (PlanNode node : toMap) {
FrameUtil.convertFrame(view, node.getGroups().iterator().next(), newGroups, inverseMap, metadata);
}
return view;
}
/**
* Search each equi-join for partitioning
*/
private List<int[]> findMatches(
Map<ElementSymbol, List<Set<Constant>>> partitionInfo,
Map<ElementSymbol, List<Set<Constant>>> partitionInfoOther,
List<Expression> expr, List<Expression> exprOther) {
List<int[]> matches = null;
for (int i = 0; i < expr.size() && matches == null; i++) {
if (!(expr.get(i) instanceof ElementSymbol) || !(exprOther.get(i) instanceof ElementSymbol)) {
continue;
}
ElementSymbol es = (ElementSymbol)expr.get(i);
ElementSymbol esOther = (ElementSymbol)exprOther.get(i);
List<Set<Constant>> partLists = partitionInfo.get(es);
List<Set<Constant>> partListsOther = partitionInfoOther.get(esOther);
if (partLists == null || partListsOther == null) {
continue;
}
matches = findMatches(partLists, partListsOther);
}
return matches;
}
/**
* Find overlaps in the given partition lists
*/
private List<int[]> findMatches(List<Set<Constant>> partLists,
List<Set<Constant>> partListsOther) {
List<int[]> matches = new LinkedList<int[]>();
for (int j = 0; j < partLists.size(); j++) {
int[] match = null;
Set<Constant> vals = partLists.get(j);
for (int k = 0; k < partListsOther.size(); k++) {
if (!Collections.disjoint(vals, partListsOther.get(k))) {
if (match == null) {
match = new int[] {j, k};
} else {
//TODO: we currently do handle a situation where multiple
//partitions overlap.
return null;
}
}
}
if (match != null) {
matches.add(match);
}
}
return matches;
}
private PlanNode buildUnion(PlanNode unionNode, PlanNode otherSide,
List<Criteria> criteria, List<int[]> matches,
List<PlanNode> branches, List<PlanNode> otherBranches) {
SymbolMap symbolMap = (SymbolMap)unionNode.getParent().getProperty(Info.SYMBOL_MAP);
SymbolMap otherSymbolMap = (SymbolMap)otherSide.getProperty(Info.SYMBOL_MAP);
List<PlanNode> joins = new LinkedList<PlanNode>();
for (int i = 0; i < matches.size(); i++) {
int[] is = matches.get(i);
PlanNode branch = branches.get(is[0]);
PlanNode branchSource = createSource(unionNode.getParent().getGroups().iterator().next(), branch, symbolMap);
PlanNode otherBranch = otherBranches.get(is[1]);
PlanNode otherBranchSource = createSource(otherSide.getGroups().iterator().next(), otherBranch, otherSymbolMap);
PlanNode newJoinNode = NodeFactory.getNewNode(NodeConstants.Types.JOIN);
newJoinNode.addLastChild(branchSource);
newJoinNode.addLastChild(otherBranchSource);
newJoinNode.setProperty(Info.JOIN_STRATEGY, JoinStrategyType.NESTED_LOOP);
newJoinNode.setProperty(Info.JOIN_TYPE, JoinType.JOIN_INNER);
newJoinNode.setProperty(Info.JOIN_CRITERIA, LanguageObject.Util.deepClone(criteria, Criteria.class));
newJoinNode.addGroups(branchSource.getGroups());
newJoinNode.addGroups(otherBranchSource.getGroups());
PlanNode projectPlanNode = NodeFactory.getNewNode(NodeConstants.Types.PROJECT);
newJoinNode.addAsParent(projectPlanNode);
Select allSymbols = new Select(symbolMap.getKeys());
allSymbols.addSymbols(otherSymbolMap.getKeys());
if (i == 0) {
QueryRewriter.makeSelectUnique(allSymbols, false);
}
projectPlanNode.setProperty(NodeConstants.Info.PROJECT_COLS, allSymbols.getSymbols());
projectPlanNode.addGroups(newJoinNode.getGroups());
joins.add(projectPlanNode);
}
PlanNode newUnion = RulePlanUnions.buildUnionTree(unionNode, joins);
return newUnion;
}
static PlanNode createSource(GroupSymbol group, PlanNode unionNode, SymbolMap symbolMap) {
PlanNode branchSource = NodeFactory.getNewNode(NodeConstants.Types.SOURCE);
branchSource.addGroup(group);
PlanNode projectNode = NodeEditor.findNodePreOrder(unionNode, NodeConstants.Types.PROJECT);
branchSource.setProperty(Info.SYMBOL_MAP, SymbolMap.createSymbolMap(symbolMap.getKeys(), (List<? extends SingleElementSymbol>)projectNode.getProperty(Info.PROJECT_COLS)));
unionNode.addAsParent(branchSource);
return branchSource;
}
@Override
public String toString() {
return "DecomposeJoin"; //$NON-NLS-1$
}
}