/**
* Copyright (C) 2009-2013 FoundationDB, LLC
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package com.foundationdb.sql.optimizer.rule;
import com.foundationdb.server.types.TKeyComparable;
import com.foundationdb.sql.optimizer.rule.cost.CostEstimator;
import com.foundationdb.sql.optimizer.rule.join_enum.*;
import com.foundationdb.sql.optimizer.rule.join_enum.DPhyp.ExpressionTables;
import com.foundationdb.sql.optimizer.rule.join_enum.DPhyp.JoinOperator;
import com.foundationdb.sql.optimizer.plan.*;
import com.foundationdb.sql.optimizer.plan.Sort.OrderByExpression;
import com.foundationdb.sql.optimizer.plan.JoinNode.JoinType;
import com.foundationdb.server.collation.AkCollator;
import com.foundationdb.server.types.common.types.StringAttribute;
import com.foundationdb.server.types.common.types.TString;
import com.foundationdb.server.types.texpressions.Comparison;
import com.foundationdb.sql.types.CharacterTypeAttributes;
import com.foundationdb.server.error.AkibanInternalException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.*;
/** Pick joins and indexes.
* This the the core of actual query optimization.
*/
public class JoinAndIndexPicker extends BaseRule
{
private static final Logger logger = LoggerFactory.getLogger(JoinAndIndexPicker.class);
@Override
protected Logger getLogger() {
return logger;
}
@Override
public void apply(PlanContext planContext) {
List<Picker> pickers = new JoinsFinder(planContext).find();
for (Picker picker : pickers) {
picker.apply();
}
}
static class Picker {
Map<SubquerySource,Picker> subpickers;
PlanContext planContext;
SchemaRulesContext rulesContext;
Joinable joinable;
BaseQuery query;
QueryIndexGoal queryGoal;
ConditionList originalSubqueryWhereConditions;
boolean enableFKJoins = true;
public Picker(Joinable joinable, BaseQuery query,
PlanContext planContext,
Map<SubquerySource,Picker> subpickers) {
this.subpickers = subpickers;
this.planContext = planContext;
this.rulesContext = (SchemaRulesContext)planContext.getRulesContext();
this.joinable = joinable;
this.query = query;
}
public CostEstimator getCostEstimator() {
return rulesContext.getCostEstimator();
}
public PlanContext getPlanContext() {
return planContext;
}
public Joinable rootJoin() {
return joinable;
}
public void apply() {
queryGoal = determineQueryIndexGoal(joinable);
if (joinable instanceof TableGroupJoinTree) {
// Single group.
pickIndex((TableGroupJoinTree)joinable);
}
else if (joinable instanceof JoinNode) {
// General joins.
pickJoinsAndIndexes ((JoinNode)joinable);
}
else if (joinable instanceof SubquerySource) {
// Single subquery // view. Just do its insides.
subpicker((SubquerySource)joinable).apply();
}
// TODO: Any other degenerate cases?
}
protected QueryIndexGoal determineQueryIndexGoal(PlanNode input) {
ConditionList whereConditions = null;
Sort ordering = null;
AggregateSource grouping = null;
Project projectDistinct = null;
Limit limit = null;
input = input.getOutput();
if (input instanceof Select) {
whereConditions = ((Select)input).getConditions();
}
input = input.getOutput();
if (input instanceof Sort) {
ordering = (Sort)input;
input = input.getOutput();
if (input instanceof Project)
input = input.getOutput();
}
else if (input instanceof AggregateSource) {
grouping = (AggregateSource)input;
if (!grouping.hasGroupBy())
grouping = null;
input = input.getOutput();
if (input instanceof Select)
input = input.getOutput();
if (input instanceof Sort) {
// Needs to be possible to satisfy both.
ordering = (Sort)input;
if (grouping != null) {
List<ExpressionNode> groupBy = grouping.getGroupBy();
for (OrderByExpression orderBy : ordering.getOrderBy()) {
ExpressionNode orderByExpr = orderBy.getExpression();
if (!((orderByExpr.isColumn() &&
(((ColumnExpression)orderByExpr).getTable() == grouping)) ||
groupBy.contains(orderByExpr))) {
ordering = null;
break;
}
}
}
if (ordering != null) // No limit if sort lost.
input = input.getOutput();
}
if (input instanceof Project)
input = input.getOutput();
}
else if (input instanceof Project) {
Project project = (Project)input;
input = project.getOutput();
if (input instanceof Distinct) {
projectDistinct = project;
input = input.getOutput();
}
else if (input instanceof Sort) {
ordering = (Sort)input;
input = input.getOutput();
if (input instanceof Distinct)
input = input.getOutput(); // Not projectDistinct (already marked as explicitly sorted).
}
}
if (input instanceof Limit)
limit = (Limit)input;
return new QueryIndexGoal(query, rulesContext, whereConditions,
grouping, ordering, projectDistinct, limit);
}
// Only a single group of tables. Don't need to run general
// join algorithm and can shortcut some of the setup for this
// group.
protected void pickIndex(TableGroupJoinTree tables) {
GroupIndexGoal groupGoal = new GroupIndexGoal(queryGoal, tables, planContext);
List<JoinOperator> empty = Collections.emptyList(); // No more joins / bound tables.
groupGoal.updateRequiredColumns(empty, empty);
BaseScan scan = groupGoal.pickBestScan();
groupGoal.install(scan, null, true, false);
query.setCostEstimate(scan.getCostEstimate());
}
protected void pickJoinsAndIndexes (JoinNode joins) {
Plan rootPlan = pickRootJoinPlan(joins);
installPlan (rootPlan, false);
}
protected Plan pickRootJoinPlan (JoinNode joins) {
JoinEnumerator processor = new JoinEnumerator (this);
List<Joinable> tables = new ArrayList<>();
JoinEnumerator.addTables(joins, tables);
int threshold = Integer.parseInt(rulesContext.getProperty("fk_join_threshold", "8"));
int tableCount = tables.size();
// Do the full JoinEnumeration processing if
// The number of tables in the set is smaller than our configuration threshold OR
// The top join in the query isn't a FK join.
if (tableCount <= threshold || ((JoinNode)joinable).getFKJoin() == null) {
return processor.run(joins, queryGoal.getWhereConditions()).bestPlan(Collections.<JoinOperator>emptyList());
} else {
processor.init(joins, null);
}
// The code that follows has been extracted and simplified from
// the processor.init() and processor.run() methods to handle the
// one join case
List<JoinOperator> operators = new ArrayList<>();
JoinOperator op = new JoinOperator(joins);
operators.add(op);
long leftTable = JoinableBitSet.empty();
long rightTable = JoinableBitSet.empty();
if (joins.getLeft() instanceof TableGroupJoinTree) {
leftTable = processor.getTableBit(joins.getLeft());
}
if (joins.getRight() instanceof TableGroupJoinTree) {
rightTable = processor.getTableBit(joins.getRight());
}
ExpressionTables visitor = new ExpressionTables(processor.getTableBitSets());
//protected void addWhereConditions(ConditionList whereConditions, ExpressionTables visitor) {
Iterator<ConditionExpression> iter = queryGoal.getWhereConditions().iterator();
while (iter.hasNext()) {
ConditionExpression condition = iter.next();
if (condition instanceof ComparisonCondition) {
ComparisonCondition comp = (ComparisonCondition)condition;
long columnTables = columnReferenceTable(comp.getLeft(), processor.getTableBitSets());
if (!JoinableBitSet.isEmpty(columnTables)) {
long rhs = visitor.getTables(comp.getRight());
if (visitor.wasNullTolerant()) continue;
if (!JoinableBitSet.isEmpty(rhs) &&
!JoinableBitSet.overlaps(columnTables, rhs) &&
joins.getFKJoin().getConditions().contains(comp)) {
operators.add(new JoinOperator(comp, columnTables, rhs));
iter.remove();
continue;
}
}
columnTables = columnReferenceTable(comp.getRight(), processor.getTableBitSets());
if (!JoinableBitSet.isEmpty(columnTables)) {
long lhs = visitor.getTables(comp.getLeft());
if (visitor.wasNullTolerant()) continue;
if (!JoinableBitSet.isEmpty(lhs) &&
!JoinableBitSet.overlaps(columnTables, lhs) &&
joins.getFKJoin().getConditions().contains(comp)) {
operators.add(new JoinOperator(comp, columnTables, lhs));
iter.remove();
continue;
}
}
}
}
List<JoinOperator> outsideJoins = new ArrayList<>();
outsideJoins.addAll(operators); // Total set for outer; inner must subtract.
PlanClass leftClass = null;
Plan leftPlan = null;
Plan rightPlan = null;
if (joins.getLeft() instanceof TableGroupJoinTree) {
leftClass = processor.evaluateTable(leftTable, joins.getLeft());
leftPlan = leftClass.bestPlan(outsideJoins);
} else if (joins.getLeft() instanceof JoinNode) {
if (((JoinNode)joins.getLeft()).getFKJoin() != null) {
leftClass = new JoinPlanClass(processor, processor.rootJoinLeftTables());
leftPlan = pickRootJoinPlan((JoinNode) joins.getLeft());
} else {
JoinEnumerator innerProcessor = new JoinEnumerator (this);
leftClass = innerProcessor.run(joins.getLeft(), queryGoal.getWhereConditions());
leftPlan = leftClass.bestPlan(Collections.<JoinOperator>emptyList());
}
}
if (joins.getRight() instanceof TableGroupJoinTree) {
rightPlan = processor.evaluateTable(rightTable, joins.getRight()).bestNestedPlan (leftClass, operators, outsideJoins);
} else if (joins.getRight() instanceof JoinNode) {
if (((JoinNode)joins.getRight()).getFKJoin() != null) {
rightPlan = pickRootJoinPlan((JoinNode)joins.getRight());
} else {
JoinEnumerator innerProcessor = new JoinEnumerator (this);
rightPlan = innerProcessor.run(joins.getRight(), queryGoal.getWhereConditions()).bestPlan(Collections.<JoinOperator>emptyList());
}
}
JoinType joinType = joins.getJoinType();
CostEstimate costEstimate = leftPlan.costEstimate.nest(rightPlan.costEstimate);
JoinPlan joinPlan = new JoinPlan(leftPlan, rightPlan,
joinType, JoinNode.Implementation.NESTED_LOOPS,
outsideJoins, costEstimate);
return joinPlan;
}
/** Is this a single column in a known table? */
protected static long columnReferenceTable(ExpressionNode node, Map<Joinable, Long>tableBitSets) {
if (node instanceof ColumnExpression) {
Long bitset = tableBitSets.get(
((ColumnExpression)node).getTable()
);
if (bitset != null) {
return bitset;
}
}
return JoinableBitSet.empty();
}
// Put the chosen plan in place.
public void installPlan(Plan rootPlan, boolean copy) {
joinable.getOutput().replaceInput(joinable,
moveInSemiJoins(rootPlan.install(copy)));
query.setCostEstimate(rootPlan.costEstimate);
}
// If any semi-joins to VALUES are left over at the top, they
// can be put into the Select and then possibly moved earlier.
protected Joinable moveInSemiJoins(Plan.JoinableWithConditionsToRemove joinedWithConditions) {
Joinable joined = joinedWithConditions.getJoinable();
if (queryGoal.getWhereConditions() != null) {
while (joined instanceof JoinNode) {
JoinNode join = (JoinNode)joined;
if (join.getJoinType() != JoinType.SEMI)
break;
Joinable right = join.getRight();
if (!(right instanceof ExpressionsSource))
break;
// Cf. GroupIndexGoal.semiJoinToInList.
ExpressionsSource values = (ExpressionsSource)right;
ComparisonCondition ccond = null;
boolean found = false;
if ((join.getJoinConditions() != null) &&
(join.getJoinConditions().size() == 1)) {
ConditionExpression joinCondition = join.getJoinConditions().get(0);
if (joinCondition instanceof ComparisonCondition) {
ccond = (ComparisonCondition)joinCondition;
if ((ccond.getOperation() == Comparison.EQ) &&
(ccond.getRight() instanceof ColumnExpression)) {
ColumnExpression rcol = (ColumnExpression)ccond.getRight();
if ((rcol.getTable() == values) &&
(rcol.getPosition() == 0)) {
found = true;
}
}
}
}
if (!found) break;
// Replace semi-join with In Select condition.
queryGoal.getWhereConditions()
.add(GroupIndexGoal.semiJoinToInList(values, ccond, rulesContext));
joined = join.getLeft();
}
}
return joined;
}
// Get the handler for the given subquery so that it can be done in context.
public Picker subpicker(SubquerySource subquery) {
Picker subpicker = subpickers.get(subquery);
assert (subpicker != null);
return subpicker;
}
// Subquery but as part of a larger plan tree. Return best
// plan to be installed with it.
public Plan subqueryPlan(Set<ColumnSource> subqueryBoundTables,
Collection<JoinOperator> subqueryJoins,
Collection<JoinOperator> subqueryOutsideJoins) {
if (queryGoal == null) {
queryGoal = determineQueryIndexGoal(joinable);
if (queryGoal.getWhereConditions() != null)
originalSubqueryWhereConditions = new ConditionList(queryGoal.getWhereConditions());
}
if (joinable instanceof TableGroupJoinTree) {
TableGroupJoinTree tables = (TableGroupJoinTree)joinable;
GroupIndexGoal groupGoal = new GroupIndexGoal(queryGoal, tables, planContext);
// In this block because we were not a JoinNode, query has no joins itself
List<JoinOperator> queryJoins = Collections.emptyList();
List<ConditionList> conditionSources = groupGoal.updateContext(subqueryBoundTables, queryJoins, subqueryJoins,
subqueryOutsideJoins, subqueryJoins, true, null);
BaseScan scan = groupGoal.pickBestScan();
CostEstimate costEstimate = scan.getCostEstimate();
return new GroupPlan(groupGoal, JoinableBitSet.of(0), scan, costEstimate, conditionSources, true, null);
}
if (joinable instanceof JoinNode) {
if ((originalSubqueryWhereConditions != null) &&
(originalSubqueryWhereConditions.size() != queryGoal.getWhereConditions().size())) {
// Restore possible join conditions for new enumerator.
queryGoal.getWhereConditions().clear();
queryGoal.getWhereConditions().addAll(originalSubqueryWhereConditions);
}
return new JoinEnumerator(this, subqueryBoundTables, subqueryJoins, subqueryOutsideJoins).run((JoinNode)joinable, queryGoal.getWhereConditions()).bestPlan(Collections.<JoinOperator>emptyList());
}
if (joinable instanceof SubquerySource) {
SubquerySource subquerySource = (SubquerySource) joinable;
Plan plan = subpicker(subquerySource).subqueryPlan(subqueryBoundTables, subqueryJoins, subqueryOutsideJoins);
return new SubqueryPlan(subquerySource, subpicker(subquerySource), JoinableBitSet.of(0), plan, plan.costEstimate);
}
if (joinable instanceof CreateAs) {
return null;
}
if (joinable instanceof ExpressionsSource) {
CostEstimator costEstimator = this.getCostEstimator();
return new ValuesPlan((ExpressionsSource)joinable, costEstimator.costValues((ExpressionsSource)joinable, false));
}
throw new AkibanInternalException("Unknown join element: " + joinable);
}
}
public static abstract class Plan implements Comparable<Plan> {
CostEstimate costEstimate;
protected Plan(CostEstimate costEstimate) {
this.costEstimate = costEstimate;
}
public int compareTo(Plan other) {
return costEstimate.compareTo(other.costEstimate);
}
public abstract JoinableWithConditionsToRemove install(boolean copy);
public void addDistinct() {
throw new UnsupportedOperationException();
}
public boolean semiJoinEquivalent() {
return false;
}
public boolean containsColumn(ColumnExpression column) {
return false;
}
public Collection<? extends ColumnSource> columnTables() {
return Collections.emptyList();
}
public double joinSelectivity() {
return 1.0;
}
public void redoCostWithLimit(long limit) {
}
public abstract Collection<? extends ConditionExpression> getConditions();
public static class JoinableWithConditionsToRemove {
public Joinable joinable;
public List<? extends ConditionExpression> conditions;
public JoinableWithConditionsToRemove(Joinable joinable, List<? extends ConditionExpression> conditions) {
this.joinable = joinable;
this.conditions = conditions;
}
public Joinable getJoinable() {
return joinable;
}
public List<? extends ConditionExpression> getConditions() {
return conditions;
}
}
}
static abstract class PlanClass {
JoinEnumerator enumerator;
long bitset;
protected PlanClass(JoinEnumerator enumerator, long bitset) {
this.enumerator = enumerator;
this.bitset = bitset;
}
public abstract Plan bestPlan(Collection<JoinOperator> outsideJoins);
public Plan bestNestedPlan(PlanClass outerPlan, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
return bestPlan(outsideJoins); // By default, side doesn't matter.
}
public abstract Plan bestPlan(Collection<JoinOperator> condJoins, Collection<JoinOperator> outsideJoins);
}
static class GroupPlan extends Plan {
GroupIndexGoal groupGoal;
long outerTables;
BaseScan scan;
List<ConditionList> conditionSources;
boolean sortAllowed;
ConditionList extraConditions;
public GroupPlan(GroupIndexGoal groupGoal,
long outerTables, BaseScan scan,
CostEstimate costEstimate,
List<ConditionList> conditionSources,
boolean sortAllowed,
ConditionList extraConditions) {
super(costEstimate);
this.groupGoal = groupGoal;
this.outerTables = outerTables;
this.scan = scan;
this.conditionSources = conditionSources;
this.sortAllowed = sortAllowed;
this.extraConditions = extraConditions;
}
@Override
public String toString() {
return scan.toString();
}
@Override
public JoinableWithConditionsToRemove install(boolean copy) {
if (extraConditions != null) {
// Move to WHERE clause or join condition so that any
// that survive indexing are preserved.
assert ((conditionSources.size() > 1) &&
(conditionSources.indexOf(extraConditions) > 0));
conditionSources.get(0).addAll(extraConditions);
}
return groupGoal.install(scan, conditionSources, sortAllowed, copy);
}
public boolean orderedForDistinct(Distinct distinct) {
if (!((distinct.getInput() instanceof Project) &&
(scan instanceof IndexScan)))
return false;
return groupGoal.orderedForDistinct((Project) distinct.getInput(), (IndexScan) scan);
}
@Override
public boolean semiJoinEquivalent() {
return groupGoal.semiJoinEquivalent(scan);
}
@Override
public boolean containsColumn(ColumnExpression column) {
ColumnSource table = column.getTable();
if (!(table instanceof TableSource)) return false;
return groupGoal.getTables().containsTable((TableSource) table);
}
@Override
public Collection<? extends ColumnSource> columnTables() {
return groupGoal.getTableColumnSources();
}
@Override
public double joinSelectivity() {
if (scan instanceof IndexScan)
return groupGoal.estimateSelectivity((IndexScan)scan);
else
return super.joinSelectivity();
}
@Override
public void redoCostWithLimit(long limit) {
if (scan instanceof IndexScan) {
costEstimate = groupGoal.estimateCost((IndexScan)scan, limit);
}
}
@Override
public Collection<? extends ConditionExpression> getConditions() {
return scan.getConditions();
}
}
static class GroupPlanClass extends PlanClass {
GroupIndexGoal groupGoal;
Collection<GroupPlan> bestPlans = new ArrayList<>();
public GroupPlanClass(JoinEnumerator enumerator, long bitset,
GroupIndexGoal groupGoal) {
super(enumerator, bitset);
this.groupGoal = groupGoal;
}
protected GroupPlanClass(GroupPlanClass other) {
super(other.enumerator, other.bitset);
this.groupGoal = other.groupGoal;
}
@Override
public String toString() {
return groupGoal.toString();
}
@Override
public Plan bestPlan(Collection<JoinOperator> outsideJoins) {
return bestPlan(JoinableBitSet.empty(), Collections.<JoinOperator>emptyList(), outsideJoins);
}
@Override
public Plan bestNestedPlan(PlanClass outerPlan, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
return bestPlan(outerPlan.bitset, joins, outsideJoins);
}
@Override
public Plan bestPlan(Collection<JoinOperator> condJoins, Collection<JoinOperator> outsideJoins) {
return bestPlan(JoinableBitSet.empty(), Collections.<JoinOperator>emptyList(), condJoins, outsideJoins);
}
protected ConditionList getExtraConditions() {
return null;
}
protected GroupPlan bestPlan(long outerTables, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
return bestPlan(outerTables, joins, joins, outsideJoins);
}
protected GroupPlan bestPlan(long outerTables, Collection<JoinOperator> queryJoins, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
for (GroupPlan groupPlan : bestPlans) {
if (groupPlan.outerTables == outerTables) {
return groupPlan;
}
}
boolean sortAllowed = queryJoins.isEmpty();
Collection<JoinOperator> requiredJoins = joins;
if (JoinableBitSet.isEmpty(outerTables)) {
// this is an outer plan
requiredJoins = new ArrayList<>();
joinsForOuterPlan(joins, bitset, requiredJoins);
}
List<ConditionList> conditionSources = groupGoal.updateContext(
enumerator.boundTables(outerTables), queryJoins, joins, outsideJoins, requiredJoins,
sortAllowed, getExtraConditions());
BaseScan scan = groupGoal.pickBestScan();
CostEstimate costEstimate = scan.getCostEstimate();
GroupPlan groupPlan = new GroupPlan(groupGoal, outerTables, scan, costEstimate, conditionSources, sortAllowed, getExtraConditions());
bestPlans.add(groupPlan);
return groupPlan;
}
private void joinsForOuterPlan(Collection<JoinOperator> condJoins, long bitset,
Collection<JoinOperator> joinsForLeft) {
for (JoinOperator join : condJoins) {
if (JoinableBitSet.isSubset(join.getTables(), bitset)) {
joinsForLeft.add(join);
}
}
}
}
static class GroupWithInPlanClass extends GroupPlanClass {
ConditionList inConditions;
public GroupWithInPlanClass(GroupPlanClass left,
ValuesPlanClass right,
Collection<JoinOperator> joins) {
super(left);
InListCondition incond = left.groupGoal.semiJoinToInList(right.plan.values, joins);
if (incond != null) {
inConditions = new ConditionList(1);
inConditions.add(incond);
}
}
public GroupWithInPlanClass(GroupWithInPlanClass left,
ValuesPlanClass right,
Collection<JoinOperator> joins) {
super(left);
InListCondition incond = left.groupGoal.semiJoinToInList(right.plan.values, joins);
if (incond != null) {
inConditions = new ConditionList(left.inConditions);
inConditions.add(incond);
}
}
@Override
protected ConditionList getExtraConditions() {
return inConditions;
}
}
static class SubqueryPlan extends Plan {
SubquerySource subquery;
Picker picker;
long outerTables;
Plan rootPlan;
public SubqueryPlan(SubquerySource subquery, Picker picker,
long outerTables, Plan rootPlan,
CostEstimate costEstimate) {
super(costEstimate);
this.subquery = subquery;
this.picker = picker;
this.outerTables = outerTables;
this.rootPlan = rootPlan;
}
@Override
public String toString() {
return rootPlan.toString();
}
@Override
public JoinableWithConditionsToRemove install(boolean copy) {
picker.installPlan(rootPlan, copy);
return new JoinableWithConditionsToRemove(subquery, new ConditionList());
}
@Override
public void addDistinct() {
Subquery output = subquery.getSubquery();
PlanNode input = output.getInput();
Distinct distinct = new Distinct(input);
output.replaceInput(input, distinct);
if ((rootPlan instanceof GroupPlan) &&
((GroupPlan)rootPlan).orderedForDistinct(distinct)) {
distinct.setImplementation(Distinct.Implementation.PRESORTED);
}
}
@Override
public Collection<? extends ConditionExpression> getConditions() {
return null;
}
}
static class SubqueryPlanClass extends PlanClass {
SubquerySource subquery;
Picker picker;
Collection<SubqueryPlan> bestPlans = new ArrayList<>();
public SubqueryPlanClass(JoinEnumerator enumerator, long bitset,
SubquerySource subquery, Picker picker) {
super(enumerator, bitset);
this.subquery = subquery;
this.picker = picker;
}
@Override
public String toString() {
return subquery.toString();
}
@Override
public Plan bestPlan(Collection<JoinOperator> outsideJoins) {
return bestPlan(JoinableBitSet.empty(), Collections.<JoinOperator>emptyList(), outsideJoins);
}
@Override
public Plan bestNestedPlan(PlanClass outerPlan, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
return bestPlan(outerPlan.bitset, joins, outsideJoins);
}
@Override
public Plan bestPlan(Collection<JoinOperator> condJoins, Collection<JoinOperator> outsideJoins) {
return bestPlan(JoinableBitSet.empty(), condJoins, outsideJoins);
}
protected SubqueryPlan bestPlan(long outerTables, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
for (SubqueryPlan subqueryPlan : bestPlans) {
if (subqueryPlan.outerTables == outerTables) {
return subqueryPlan;
}
}
Plan rootPlan = picker.subqueryPlan(enumerator.boundTables(outerTables), joins, outsideJoins);
CostEstimate costEstimate = rootPlan.costEstimate;
SubqueryPlan subqueryPlan = new SubqueryPlan(subquery, picker,
outerTables, rootPlan,
costEstimate);
bestPlans.add(subqueryPlan);
return subqueryPlan;
}
}
static class ValuesPlan extends Plan {
ExpressionsSource values;
public ValuesPlan(ExpressionsSource values, CostEstimate costEstimate) {
super(costEstimate);
this.values = values;
}
@Override
public String toString() {
return values.getName();
}
@Override
public JoinableWithConditionsToRemove install(boolean copy) {
return new JoinableWithConditionsToRemove(values, new ConditionList());
}
@Override
public void addDistinct() {
values.setDistinctState(ExpressionsSource.DistinctState.NEED_DISTINCT);
}
@Override
public Collection<? extends ConditionExpression> getConditions() {
return null;
}
}
static class ValuesPlanClass extends PlanClass {
ValuesPlan plan, nestedPlan;
public ValuesPlanClass(JoinEnumerator enumerator, long bitset,
ExpressionsSource values, Picker picker) {
super(enumerator, bitset);
CostEstimator costEstimator = picker.getCostEstimator();
this.plan = new ValuesPlan(values, costEstimator.costValues(values, false));
// Nested also needs to check the join condition with Select.
this.nestedPlan = new ValuesPlan(values, costEstimator.costValues(values, true));
}
@Override
public String toString() {
return plan.toString();
}
@Override
public Plan bestPlan(Collection<JoinOperator> outsideJoins) {
return plan;
}
@Override
public Plan bestNestedPlan(PlanClass outerPlan, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
return nestedPlan;
}
@Override
public Plan bestPlan(Collection<JoinOperator> condJoins, Collection<JoinOperator> outsideJoins) {
return plan;
}
}
static class CreateAsPlanClass extends PlanClass {
CreateAsPlan plan, nestedPlan;
public CreateAsPlanClass(JoinEnumerator enumerator, long bitset,
CreateAs values, Picker picker) {
super(enumerator, bitset);
CostEstimator costEstimator = picker.getCostEstimator();
this.plan = new CreateAsPlan(values, costEstimator.costBoundRow());
}
@Override
public String toString() {
return plan.toString();
}
@Override
public Plan bestPlan(Collection<JoinOperator> outsideJoins) {
return plan;
}
@Override
public Plan bestNestedPlan(PlanClass outerPlan, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
return nestedPlan;
}
@Override
public Plan bestPlan(Collection<JoinOperator> condJoins, Collection<JoinOperator> outsideJoins) {
return plan;
}
}
static class CreateAsPlan extends Plan {
CreateAs values;
public CreateAsPlan(CreateAs values, CostEstimate costEstimate) {
super(costEstimate);
this.values = values;
}
@Override
public String toString() {
return values.getName();
}
@Override
public JoinableWithConditionsToRemove install(boolean copy) {
return new JoinableWithConditionsToRemove(values, null);
}
@Override
public Collection<? extends ConditionExpression> getConditions() {
return null;
}
}
static class JoinPlan extends Plan {
Plan left, right;
JoinType joinType;
JoinNode.Implementation joinImplementation;
Collection<JoinOperator> joins;
boolean needDistinct;
public JoinPlan(Plan left, Plan right,
JoinType joinType, JoinNode.Implementation joinImplementation,
Collection<JoinOperator> joins, CostEstimate costEstimate) {
super(costEstimate);
this.left = left;
this.right = right;
switch (joinType) {
case SEMI_INNER_ALREADY_DISTINCT:
case SEMI_INNER_IF_DISTINCT:
this.joinType = JoinType.SEMI;
break;
case INNER_NEED_DISTINCT:
this.joinType = JoinType.INNER;
needDistinct = true;
break;
default:
this.joinType = joinType;
}
this.joinImplementation = joinImplementation;
this.joins = joins;
}
@Override
public String toString() {
return "(" + left + ") " +
joinType + "/" + joinImplementation +
" (" + right + ")";
}
@Override
public JoinableWithConditionsToRemove install(boolean copy) {
if (needDistinct)
left.addDistinct();
JoinableWithConditionsToRemove leftJoinable = left.install(copy);
JoinableWithConditionsToRemove rightJoinable = right.install(copy);
ConditionList conditionsToRemove = new ConditionList();
if (leftJoinable.getConditions() != null) {
conditionsToRemove.addAll(leftJoinable.getConditions());
}
if (rightJoinable.getConditions() != null) {
conditionsToRemove.addAll(rightJoinable.getConditions());
}
ConditionList joinConditions = mergeJoinConditions(joins);
if (joinConditions != null) {
joinConditions.removeAll(conditionsToRemove);
conditionsToRemove.addAll(joinConditions);
}
JoinNode join = new JoinNode(leftJoinable.getJoinable(), rightJoinable.getJoinable(), joinType);
join.setJoinConditions(joinConditions);
join.setImplementation(joinImplementation);
if (joinType == JoinType.SEMI)
InConditionReverser.cleanUpSemiJoin(join, rightJoinable.getJoinable());
return new JoinableWithConditionsToRemove(join, conditionsToRemove);
}
protected ConditionList mergeJoinConditions(Collection<JoinOperator> joins) {
ConditionList joinConditions = null;
boolean newJoinConditions = false;
for (JoinOperator joinOp : joins) {
if ((joinOp.getJoinConditions() != null) &&
!joinOp.getJoinConditions().isEmpty()) {
if (joinConditions == null) {
joinConditions = joinOp.getJoinConditions();
}
else {
if (!newJoinConditions) {
joinConditions = new ConditionList(joinConditions);
newJoinConditions = true;
}
joinConditions.addAll(joinOp.getJoinConditions());
}
}
}
return joinConditions;
}
public void redoCostWithLimit(long limit) {
left.redoCostWithLimit(limit);
costEstimate = left.costEstimate.nest(right.costEstimate);
}
@Override
public Collection<? extends ConditionExpression> getConditions() {
return null;
}
}
static class HashJoinPlan extends JoinPlan {
Plan loader;
BaseHashTable hashTable;
List<ExpressionNode> hashColumns, matchColumns;
List<TKeyComparable> tKeyComparables ;
List<AkCollator> collators;
public HashJoinPlan(Plan loader, Plan input, Plan check,
JoinType joinType, JoinNode.Implementation joinImplementation,
Collection<JoinOperator> joins, CostEstimate costEstimate,
BaseHashTable hashTable, List<ExpressionNode> hashColumns, List<ExpressionNode> matchColumns,
List<TKeyComparable> tKeyComparables, List<AkCollator> collators
) {
super(input, check, joinType, joinImplementation, joins, costEstimate);
this.loader = loader;
this.hashTable = hashTable;
this.hashColumns = hashColumns;
this.matchColumns = matchColumns;
this.tKeyComparables = tKeyComparables;
this.collators = collators;
}
@Override
public JoinableWithConditionsToRemove install(boolean copy) {
if (needDistinct)
left.addDistinct();
JoinableWithConditionsToRemove loaderJoinable = loader.install(true);
JoinableWithConditionsToRemove inputJoinable = left.install(copy);
JoinableWithConditionsToRemove checkJoinable = right.install(copy);
ConditionList joinConditions = mergeJoinConditions(joins);
if (loaderJoinable.getConditions() != null) {
joinConditions.removeAll(loaderJoinable.getConditions());
}
if (inputJoinable.getConditions() != null) {
joinConditions.removeAll(inputJoinable.getConditions());
}
if (checkJoinable.getConditions() != null) {
joinConditions.removeAll(checkJoinable.getConditions());
}
// the output is different in the planString if joinConditions is null vs. empty
// so make it null here to make the tests happier
if (joinConditions == null || joinConditions.isEmpty()) {
joinConditions = null;
}
HashJoinNode join = new HashJoinNode(loaderJoinable.getJoinable(), inputJoinable.getJoinable(), checkJoinable.getJoinable(),
joinType, hashTable, hashColumns, matchColumns, tKeyComparables, collators);
join.setJoinConditions(joinConditions);
join.setImplementation(joinImplementation);
if (joinType == JoinType.SEMI)
InConditionReverser.cleanUpSemiJoin(join, checkJoinable.getJoinable());
return new JoinableWithConditionsToRemove(join, new ConditionList());
}
}
static class JoinPlanClass extends PlanClass {
Plan bestPlan; // TODO: Later have separate sorted, etc.
GroupWithInPlanClass asGroupWithIn; // If semi-joined to one or more VALUES.
public JoinPlanClass(JoinEnumerator enumerator, long bitset) {
super(enumerator, bitset);
}
@Override
public String toString() {
return bestPlan.toString();
}
@Override
public Plan bestPlan(Collection<JoinOperator> outsideJoins) {
return bestPlan;
}
@Override
public Plan bestPlan(Collection<JoinOperator> condJoins, Collection<JoinOperator> outsideJoins) {
return bestPlan;
}
public void consider(Plan plan) {
if (bestPlan == null) {
logger.debug("Selecting {}, {}", plan, plan.costEstimate);
bestPlan = plan;
}
else if (bestPlan.compareTo(plan) > 0) {
logger.debug("Preferring {}, {}", plan, plan.costEstimate);
bestPlan = plan;
}
else {
logger.debug("Rejecting {}, {}", plan, plan.costEstimate);
}
}
}
static class JoinEnumerator extends DPhyp<PlanClass> {
private Picker picker;
private Set<ColumnSource> subqueryBoundTables;
private Collection<JoinOperator> subqueryJoins, subqueryOutsideJoins;
public JoinEnumerator(Picker picker) {
this.picker = picker;
}
public JoinEnumerator(Picker picker, Set<ColumnSource> subqueryBoundTables, Collection<JoinOperator> subqueryJoins, Collection<JoinOperator> subqueryOutsideJoins) {
this.picker = picker;
this.subqueryBoundTables = subqueryBoundTables;
this.subqueryJoins = subqueryJoins;
this.subqueryOutsideJoins = subqueryOutsideJoins;
}
@Override
public PlanClass evaluateTable(long s, Joinable joinable) {
// Seed with the right plan class to hold state / alternatives.
if (joinable instanceof TableGroupJoinTree) {
GroupIndexGoal groupGoal = new GroupIndexGoal(picker.queryGoal,
(TableGroupJoinTree)joinable, picker.getPlanContext());
return new GroupPlanClass(this, s, groupGoal);
}
if (joinable instanceof SubquerySource) {
SubquerySource subquery = (SubquerySource)joinable;
Picker subpicker = picker.subpicker(subquery);
return new SubqueryPlanClass(this, s, subquery, subpicker);
}
if (joinable instanceof ExpressionsSource) {
return new ValuesPlanClass(this, s, (ExpressionsSource)joinable, picker);
}
if (joinable instanceof CreateAs){
return new CreateAsPlanClass(this, s, (CreateAs)joinable, picker);
}
throw new AkibanInternalException("Unknown join element: " + joinable);
}
@Override
public PlanClass evaluateJoin(long leftBitset, PlanClass left,
long rightBitset, PlanClass right,
long bitset, PlanClass existing,
JoinType joinType, Collection<JoinOperator> joins, Collection<JoinOperator> outsideJoins) {
JoinPlanClass planClass = (JoinPlanClass)existing;
if (planClass == null)
planClass = new JoinPlanClass(this, bitset);
if ((joinType.isSemi() && (right instanceof ValuesPlanClass))) {
// Semi-join a VALUES on the inside by turning it into
// predicate, which can be better optimized.
assert (planClass.asGroupWithIn == null);
GroupWithInPlanClass asGroupWithIn = null;
if (left instanceof GroupPlanClass) {
asGroupWithIn = new GroupWithInPlanClass((GroupPlanClass)left,
(ValuesPlanClass)right,
joins);
}
else if (left instanceof JoinPlanClass) {
JoinPlanClass leftJoinPlanClass = (JoinPlanClass)left;
if (leftJoinPlanClass.asGroupWithIn != null) {
asGroupWithIn = new GroupWithInPlanClass(leftJoinPlanClass.asGroupWithIn,
(ValuesPlanClass)right,
joins);
}
}
if ((asGroupWithIn != null) &&
(asGroupWithIn.getExtraConditions() != null)) {
Plan withInPlan = asGroupWithIn.bestPlan(outsideJoins);
if (withInPlan != null) {
planClass.asGroupWithIn = asGroupWithIn;
planClass.consider(withInPlan);
}
return planClass;
}
}
joins = duplicateJoins(joins);
Collection<JoinOperator> condJoins = joins; // Joins with conditions for indexing.
if (subqueryJoins != null) {
// "Push down" joins into the subquery. Since these
// are joins to the dervived table, they still need to
// be recognized to match an indexable column.
condJoins = new ArrayList<>(joins);
condJoins.addAll(subqueryJoins);
}
if (subqueryOutsideJoins != null) {
outsideJoins.addAll(subqueryOutsideJoins);
}
outsideJoins.addAll(joins); // Total set for outer; inner must subtract.
// TODO: Divvy up sorting. Consider group joins. Consider merge joins.
Collection<JoinOperator> joinsForLeft = new ArrayList<>();
joinsForOuterPlan(condJoins, left, joinsForLeft);
Plan leftPlan = left.bestPlan(condJoins, outsideJoins);
Plan rightPlan = right.bestNestedPlan(left, condJoins, outsideJoins);
CostEstimate costEstimate = leftPlan.costEstimate.nest(rightPlan.costEstimate);
JoinPlan joinPlan = new JoinPlan(leftPlan, rightPlan,
joinType, JoinNode.Implementation.NESTED_LOOPS,
joins, costEstimate);
if (isFreeOfJoinCondition(leftPlan, rightPlan.getConditions())) {
List<JoinOperator> joinOperators = duplicateJoins(joins);
Plan loaderPlan = right.bestPlan(condJoins, outsideJoins);
JoinPlan hashPlan = buildHashTableJoin(loaderPlan, joinPlan, joinOperators);
if (hashPlan != null) {
planClass.consider(hashPlan);
}
}
if (joinType.isSemi() || (joinType.isInner() && rightPlan.semiJoinEquivalent())) {
Collection<JoinOperator> semiJoins = duplicateJoins(joins);
Plan loaderPlan = right.bestPlan(condJoins, outsideJoins);
cleanJoinConditions(semiJoins, loaderPlan, leftPlan);
// buildBloomFilterSemiJoin modifies the joinPlan.
JoinPlan hashPlan = buildBloomFilterSemiJoin(loaderPlan, joinPlan, semiJoins);
if (hashPlan != null)
planClass.consider(hashPlan);
}
cleanJoinConditions(joins, leftPlan, rightPlan);
planClass.consider(joinPlan);
return planClass;
}
private void joinsForOuterPlan(Collection<JoinOperator> condJoins, PlanClass left,
Collection<JoinOperator> joinsForLeft) {
for (JoinOperator join : condJoins) {
if (JoinableBitSet.isSubset(join.getTables(), left.bitset)) {
joinsForLeft.add(join);
}
}
}
private void cleanJoinConditions(Collection<JoinOperator> joins, Plan leftPlan, Plan rightPlan) {
Collection<? extends ConditionExpression> leftConditions = leftPlan.getConditions();
Collection<? extends ConditionExpression> rightConditions = rightPlan.getConditions();
for (JoinOperator join : joins) {
if (join.getJoinConditions() != null) {
if (leftConditions != null) {
join.getJoinConditions().removeAll(leftConditions);
}
if (rightConditions != null) {
join.getJoinConditions().removeAll(rightConditions);
}
}
}
}
private List<JoinOperator> duplicateJoins(Collection<JoinOperator> joins) {
List<JoinOperator> retJoins = new ArrayList<>();
for (JoinOperator join : joins) {
retJoins.add(new JoinOperator(join));
}
return retJoins;
}
/** Get the tables that correspond to the given bitset, plus
* any that are bound outside the subquery, either
* syntactically or via joins to it.
*/
public Set<ColumnSource> boundTables(long tables) {
if (JoinableBitSet.isEmpty(tables) &&
(subqueryBoundTables == null))
return picker.queryGoal.getQuery().getOuterTables();
Set<ColumnSource> boundTables = new HashSet<>();
boundTables.addAll(picker.queryGoal.getQuery().getOuterTables());
if (subqueryBoundTables != null)
boundTables.addAll(subqueryBoundTables);
if (!JoinableBitSet.isEmpty(tables)) {
for (int i = 0; i < 64; i++) {
if (JoinableBitSet.overlaps(tables, JoinableBitSet.of(i))) {
Joinable table = getTable(i);
if (table instanceof TableGroupJoinTree) {
for (TableGroupJoinTree.TableGroupJoinNode gtable : (TableGroupJoinTree)table) {
boundTables.add(gtable.getTable());
}
}
else {
boundTables.add((ColumnSource)table);
}
}
}
}
return boundTables;
}
double BLOOM_FILTER_MAX_SELECTIVITY_DEFAULT = 0.05;
public JoinPlan buildBloomFilterSemiJoin(Plan loaderPlan, JoinPlan joinPlan,
Collection<JoinOperator> joinOperators) {
Plan inputPlan = joinPlan.left;
Plan checkPlan = joinPlan.right;
Collection<JoinOperator> joins = joinOperators;
if (checkPlan.costEstimate.getRowCount() > 1)
return null; // Join not selective.
double maxSelectivity;
String prop = picker.rulesContext.getProperty("bloomFilterMaxSelectivity");
if (prop != null)
maxSelectivity = Double.valueOf(prop);
else
maxSelectivity = BLOOM_FILTER_MAX_SELECTIVITY_DEFAULT;
if (maxSelectivity <= 0.0) return null; // Feature turned off.
HashTableColumns hashTableColumns = hashTableColumns(joins, inputPlan, checkPlan);
if (hashTableColumns == null)
return null;
double selectivity = checkPlan.joinSelectivity();
if (selectivity > maxSelectivity)
return null;
long limit = picker.queryGoal.getLimit();
if (joinPlan.costEstimate.getRowCount() == limit) {
// If there was a limit, it was applied too liberally
// for the very non-selective join.
// TODO: This should have always been the cost of the
// join plan, but that would be too disruptive, so
// only do it when need to make the comparison with
// the Bloom filter accurate.
// Doing so would also make optimizing take longer
limit = Math.round(limit / selectivity);
joinPlan.redoCostWithLimit(limit);
}
BloomFilter bloomFilter = new BloomFilter(loaderPlan.costEstimate.getRowCount(), 1);
CostEstimate costEstimate = picker.getCostEstimator()
.costBloomFilter(loaderPlan.costEstimate, inputPlan.costEstimate, checkPlan.costEstimate, selectivity);
return new HashJoinPlan(loaderPlan, inputPlan, checkPlan,
JoinType.SEMI, JoinNode.Implementation.BLOOM_FILTER,
joins, costEstimate, bloomFilter, hashTableColumns.hashColumns, hashTableColumns.matchColumns, hashTableColumns.tKeyComparables, hashTableColumns.collators);
}
private List<JoinOperator> cleanJoinOperators(Plan inputPlan, List<JoinOperator> joinOperators) {
if (inputPlan instanceof GroupPlan && ((GroupPlan) inputPlan).scan instanceof SingleIndexScan && ((GroupPlan)inputPlan).scan.getConditions() != null) {
SingleIndexScan scan = (SingleIndexScan) ((GroupPlan) inputPlan).scan;
for (ConditionExpression indexCond : scan.getConditions()) {
if (indexCond instanceof ComparisonCondition) {
for (int i = 0; i < joinOperators.size(); i++) {
removeIfExists(indexCond, joinOperators.get(i).getJoinConditions());
if (joinOperators.get(i).getJoin() != null)
removeIfExists(indexCond, joinOperators.get(i).getJoin().getJoinConditions());
}
}
}
}
return joinOperators;
}
private void removeIfExists(ConditionExpression condToRemove, ConditionList conditionList){
if (conditionList == null || conditionList.isEmpty())
return;
for (int j = 0; j < conditionList.size(); j++) {
if (conditionList.get(j) instanceof ComparisonCondition) {
ComparisonCondition compCondition = (ComparisonCondition) conditionList.get(j);
if (compCondition.getRight() instanceof ColumnExpression && compCondition.getLeft() instanceof ColumnExpression)
continue;
if (conditionList.get(j).equals(condToRemove))
conditionList.remove(j--);
}
}
}
int MAX_COL_COUNT = 5000;
int DEFAULT_COLUMN_COUNT = 5;
public JoinPlan buildHashTableJoin(Plan loaderPlan, JoinPlan joinPlan,
List<JoinOperator> joinOperators) {
Plan outerPlan = joinPlan.left;
joinOperators = cleanJoinOperators(outerPlan, joinOperators);
Plan innerPlan = joinPlan.right;
joinOperators = cleanJoinOperators(innerPlan, joinOperators);
Collection<JoinOperator> joins = joinOperators;
HashTableColumns hashTableColumns = hashTableColumns(joins, outerPlan, innerPlan);
if (hashTableColumns == null)
return null;
String prop = picker.rulesContext.getProperty("hashTableMaxRowCount");
int maxColumnCount;
if (prop != null){
maxColumnCount = Integer.parseInt(prop);
if (maxColumnCount == 0) return null; }
else
maxColumnCount = MAX_COL_COUNT;
if (loaderPlan.costEstimate.getRowCount() * hashTableColumns.hashColumns.size() > maxColumnCount)
return null;
int outerColumnCount = DEFAULT_COLUMN_COUNT;
int innerColumnCount = DEFAULT_COLUMN_COUNT;
HashTable hashTable = new HashTable(loaderPlan.costEstimate.getRowCount());
for (ExpressionNode expression : hashTableColumns.matchColumns) {
if (expression instanceof ColumnExpression) {
ColumnSource columnSource = ((ColumnExpression)expression).getTable();
if (columnSource instanceof TableSource) {
TableNode table = ((TableSource)columnSource).getTable();
outerColumnCount = table.getTable().rowDef().getFieldCount();
break;
}
}
}
for (ExpressionNode expression : hashTableColumns.hashColumns) {
if (expression instanceof ColumnExpression) {
ColumnSource columnSource = ((ColumnExpression)expression).getTable();
if (columnSource instanceof TableSource) {
TableNode table = ((TableSource)columnSource).getTable();
innerColumnCount = table.getTable().rowDef().getFieldCount();
break;
}
}
}
CostEstimate costEstimate = picker.getCostEstimator()
.costHashLookup(innerPlan.costEstimate, hashTableColumns.hashColumns.size(), innerColumnCount);
HashLookupPlan lookupPlan = new HashLookupPlan(costEstimate, hashTable, hashTableColumns);
costEstimate = picker.getCostEstimator()
.costHashJoin(loaderPlan.costEstimate, outerPlan.costEstimate, costEstimate, hashTableColumns.hashColumns.size(), outerColumnCount, innerColumnCount);
return new HashJoinPlan(loaderPlan, outerPlan, lookupPlan,
joinPlan.joinType, JoinNode.Implementation.HASH_TABLE,
joins, costEstimate, hashTable, hashTableColumns.hashColumns, hashTableColumns.matchColumns, hashTableColumns.tKeyComparables, hashTableColumns.collators);
}
static class HashLookupPlan extends Plan {
HashTable hashTable;
HashTableColumns hashTableColumns;
public HashLookupPlan(CostEstimate costEstimate, HashTable hashTable, HashTableColumns hashTableColumns) {
super(costEstimate);
this.hashTable = hashTable;
this.hashTableColumns = hashTableColumns;
}
@Override
public String toString() {
return hashTableColumns.conditions.toString();
}
@Override
public JoinableWithConditionsToRemove install(boolean copy) {
HashTableLookup lookup = new HashTableLookup(hashTable,
hashTableColumns.matchColumns,
hashTableColumns.conditions,
hashTableColumns.tables);
return new JoinableWithConditionsToRemove(lookup,
hashTableColumns.conditions);
}
@Override
public Collection<? extends ConditionExpression> getConditions() {
return hashTableColumns.conditions;
}
}
static class HashTableColumns {
List<ConditionExpression> conditions = new ArrayList<>();
List<ExpressionNode> matchColumns = new ArrayList<>();
List<ExpressionNode> hashColumns = new ArrayList<>();
Collection<? extends ColumnSource> tables;
List<TKeyComparable> tKeyComparables = new ArrayList<>();
List<AkCollator> collators = new ArrayList<>();
}
/** Find some equality conditions between tables on the two sides of the join.
* These can be used to load a hash table / Bloom filter.
*/
public HashTableColumns hashTableColumns(Collection<JoinOperator> joins, Plan inputPlan, Plan checkPlan) {
HashTableColumns result = new HashTableColumns();
for (JoinOperator join : joins) {
if (join.getJoinConditions() != null) {
for (ConditionExpression cond : join.getJoinConditions()) {
if (!(cond instanceof ComparisonCondition)) continue;
ComparisonCondition ccond = (ComparisonCondition) cond;
if (ccond.getOperation() != Comparison.EQ) continue;
ExpressionNode left = ccond.getLeft();
ExpressionNode right = ccond.getRight();
if (!((left instanceof ColumnExpression) &&
(right instanceof ColumnExpression)))
continue;
ColumnExpression matchColumn, hashColumn;
if (inputPlan.containsColumn((ColumnExpression) left) &&
checkPlan.containsColumn((ColumnExpression) right)) {
matchColumn = (ColumnExpression) left;
hashColumn = (ColumnExpression) right;
}
else if (inputPlan.containsColumn((ColumnExpression) right) &&
checkPlan.containsColumn((ColumnExpression) left)) {
matchColumn = (ColumnExpression) right;
hashColumn = (ColumnExpression) left;
}
else continue;
result.conditions.add(cond);
result.matchColumns.add(matchColumn);
result.hashColumns.add(hashColumn);
result.tKeyComparables.add(ccond.getKeyComparable());
AkCollator collator = null;
if (left.getType().hasAttributes(StringAttribute.class) &&
right.getType().hasAttributes(StringAttribute.class)) {
CharacterTypeAttributes leftAttributes = StringAttribute.characterTypeAttributes(left.getType());
CharacterTypeAttributes rightAttributes = StringAttribute.characterTypeAttributes(right.getType());
collator = TString.mergeAkCollators(leftAttributes, rightAttributes);
}
result.collators.add(collator);
}
}
}
if (result.conditions.isEmpty())
return null;
result.tables = checkPlan.columnTables();
return result;
}
}
// Find top-level joins and note what query they come from;
// Top-level queries and those used in expressions are returned directly.
// Derived tables are deferred, since they need to be planned in
// the context of various join orders to allow for join predicated
// to be pushed "inside." So they are stored in a Map accessible
// to other Pickers.
static class JoinsFinder extends SubqueryBoundTablesTracker {
List<Picker> result;
Map<SubquerySource,Picker> subpickers;
public JoinsFinder(PlanContext planContext) {
super(planContext);
}
public List<Picker> find() {
result = new ArrayList<>();
subpickers = new HashMap<>();
run();
result.removeAll(subpickers.values()); // Do these in context.
return result;
}
@Override
public boolean visit(PlanNode n) {
super.visit(n);
if ((n instanceof Joinable) && !(n instanceof TableSource)) {
Joinable j = (Joinable)n;
while (j.getOutput() instanceof Joinable)
j = (Joinable)j.getOutput();
BaseQuery query = currentQuery();
SubquerySource subquerySource = null;
if (query.getOutput() instanceof SubquerySource)
subquerySource = (SubquerySource)query.getOutput();
for (Picker picker : result) {
if (picker.joinable == j)
// Already have another set of joins to same root join.
return true;
}
Picker picker = new Picker(j, query, planContext, subpickers);
result.add(picker);
if (subquerySource != null)
subpickers.put(subquerySource, picker);
}
return true;
}
}
/** Does this scan only handle conditions independent of the outer scan? */
public static boolean isFreeOfJoinCondition(Plan outerPlan,
Collection<? extends ConditionExpression> conditions) {
if ((conditions == null) || conditions.isEmpty())
return true;
JoinConditionChecker checker = new JoinConditionChecker(outerPlan);
for (ConditionExpression cond : conditions) {
if (!cond.accept(checker)) break;
}
return !checker.found;
}
static class JoinConditionChecker implements ExpressionVisitor {
final Plan plan;
boolean found;
public JoinConditionChecker(Plan plan) {
this.plan = plan;
}
public boolean visitEnter(ExpressionNode n) {
return visit(n);
}
public boolean visitLeave(ExpressionNode n) {
return !found;
}
public boolean visit(ExpressionNode n) {
if (n instanceof ColumnExpression) {
if (plan.containsColumn((ColumnExpression)n)) {
found = true;
}
}
return !found;
}
}
}