Examples with Project org.apache.calcite.rel.core.Project used on opensource projects

Example 6 with Project

use of org.apache.calcite.rel.core.Project in project calcite by apache.

the class RelMdColumnUniqueness method simplyProjects.

private boolean simplyProjects(RelNode rel, ImmutableBitSet columns) {
    if (!(rel instanceof Project)) {
        return false;
    }
    Project project = (Project) rel;
    final List<RexNode> projects = project.getProjects();
    for (int column : columns) {
        if (column >= projects.size()) {
            return false;
        }
        if (!(projects.get(column) instanceof RexInputRef)) {
            return false;
        }
        final RexInputRef ref = (RexInputRef) projects.get(column);
        if (ref.getIndex() != column) {
            return false;
        }
    }
    return true;
}

Example 7 with Project

use of org.apache.calcite.rel.core.Project in project calcite by apache.

the class AbstractMaterializedViewRule method perform.

/**
 * Rewriting logic is based on "Optimizing Queries Using Materialized Views:
 * A Practical, Scalable Solution" by Goldstein and Larson.
 *
 * <p>On the query side, rules matches a Project-node chain or node, where node
 * is either an Aggregate or a Join. Subplan rooted at the node operator must
 * be composed of one or more of the following operators: TableScan, Project,
 * Filter, and Join.
 *
 * <p>For each join MV, we need to check the following:
 * <ol>
 * <li> The plan rooted at the Join operator in the view produces all rows
 * needed by the plan rooted at the Join operator in the query.</li>
 * <li> All columns required by compensating predicates, i.e., predicates that
 * need to be enforced over the view, are available at the view output.</li>
 * <li> All output expressions can be computed from the output of the view.</li>
 * <li> All output rows occur with the correct duplication factor. We might
 * rely on existing Unique-Key - Foreign-Key relationships to extract that
 * information.</li>
 * </ol>
 *
 * <p>In turn, for each aggregate MV, we need to check the following:
 * <ol>
 * <li> The plan rooted at the Aggregate operator in the view produces all rows
 * needed by the plan rooted at the Aggregate operator in the query.</li>
 * <li> All columns required by compensating predicates, i.e., predicates that
 * need to be enforced over the view, are available at the view output.</li>
 * <li> The grouping columns in the query are a subset of the grouping columns
 * in the view.</li>
 * <li> All columns required to perform further grouping are available in the
 * view output.</li>
 * <li> All columns required to compute output expressions are available in the
 * view output.</li>
 * </ol>
 *
 * <p>The rule contains multiple extensions compared to the original paper. One of
 * them is the possibility of creating rewritings using Union operators, e.g., if
 * the result of a query is partially contained in the materialized view.
 */
protected void perform(RelOptRuleCall call, Project topProject, RelNode node) {
    final RexBuilder rexBuilder = node.getCluster().getRexBuilder();
    final RelMetadataQuery mq = RelMetadataQuery.instance();
    final RelOptPlanner planner = call.getPlanner();
    final RexExecutor executor = Util.first(planner.getExecutor(), RexUtil.EXECUTOR);
    final RelOptPredicateList predicates = RelOptPredicateList.EMPTY;
    final RexSimplify simplify = new RexSimplify(rexBuilder, predicates, true, executor);
    final List<RelOptMaterialization> materializations = (planner instanceof VolcanoPlanner) ? ((VolcanoPlanner) planner).getMaterializations() : ImmutableList.<RelOptMaterialization>of();
    if (!materializations.isEmpty()) {
        // try to generate a rewriting are met
        if (!isValidPlan(topProject, node, mq)) {
            return;
        }
        // Obtain applicable (filtered) materializations
        // TODO: Filtering of relevant materializations needs to be
        // improved so we gather only materializations that might
        // actually generate a valid rewriting.
        final List<RelOptMaterialization> applicableMaterializations = RelOptMaterializations.getApplicableMaterializations(node, materializations);
        if (!applicableMaterializations.isEmpty()) {
            // 2. Initialize all query related auxiliary data structures
            // that will be used throughout query rewriting process
            // Generate query table references
            final Set<RelTableRef> queryTableRefs = mq.getTableReferences(node);
            if (queryTableRefs == null) {
                // Bail out
                return;
            }
            // Extract query predicates
            final RelOptPredicateList queryPredicateList = mq.getAllPredicates(node);
            if (queryPredicateList == null) {
                // Bail out
                return;
            }
            final RexNode pred = simplify.simplify(RexUtil.composeConjunction(rexBuilder, queryPredicateList.pulledUpPredicates, false));
            final Triple<RexNode, RexNode, RexNode> queryPreds = splitPredicates(rexBuilder, pred);
            // Extract query equivalence classes. An equivalence class is a set
            // of columns in the query output that are known to be equal.
            final EquivalenceClasses qEC = new EquivalenceClasses();
            for (RexNode conj : RelOptUtil.conjunctions(queryPreds.getLeft())) {
                assert conj.isA(SqlKind.EQUALS);
                RexCall equiCond = (RexCall) conj;
                qEC.addEquivalenceClass((RexTableInputRef) equiCond.getOperands().get(0), (RexTableInputRef) equiCond.getOperands().get(1));
            }
            // rewrite the given query
            for (RelOptMaterialization materialization : applicableMaterializations) {
                RelNode view = materialization.tableRel;
                Project topViewProject;
                RelNode viewNode;
                if (materialization.queryRel instanceof Project) {
                    topViewProject = (Project) materialization.queryRel;
                    viewNode = topViewProject.getInput();
                } else {
                    topViewProject = null;
                    viewNode = materialization.queryRel;
                }
                // 3.1. View checks before proceeding
                if (!isValidPlan(topViewProject, viewNode, mq)) {
                    // Skip it
                    continue;
                }
                // 3.2. Initialize all query related auxiliary data structures
                // that will be used throughout query rewriting process
                // Extract view predicates
                final RelOptPredicateList viewPredicateList = mq.getAllPredicates(viewNode);
                if (viewPredicateList == null) {
                    // Skip it
                    continue;
                }
                final RexNode viewPred = simplify.simplify(RexUtil.composeConjunction(rexBuilder, viewPredicateList.pulledUpPredicates, false));
                final Triple<RexNode, RexNode, RexNode> viewPreds = splitPredicates(rexBuilder, viewPred);
                // Extract view table references
                final Set<RelTableRef> viewTableRefs = mq.getTableReferences(viewNode);
                if (viewTableRefs == null) {
                    // Bail out
                    return;
                }
                // Extract view tables
                MatchModality matchModality;
                Multimap<RexTableInputRef, RexTableInputRef> compensationEquiColumns = ArrayListMultimap.create();
                if (!queryTableRefs.equals(viewTableRefs)) {
                    // subset of query tables (add additional tables through joins if possible)
                    if (viewTableRefs.containsAll(queryTableRefs)) {
                        matchModality = MatchModality.QUERY_PARTIAL;
                        final EquivalenceClasses vEC = new EquivalenceClasses();
                        for (RexNode conj : RelOptUtil.conjunctions(viewPreds.getLeft())) {
                            assert conj.isA(SqlKind.EQUALS);
                            RexCall equiCond = (RexCall) conj;
                            vEC.addEquivalenceClass((RexTableInputRef) equiCond.getOperands().get(0), (RexTableInputRef) equiCond.getOperands().get(1));
                        }
                        if (!compensatePartial(viewTableRefs, vEC, queryTableRefs, compensationEquiColumns)) {
                            // Cannot rewrite, skip it
                            continue;
                        }
                    } else if (queryTableRefs.containsAll(viewTableRefs)) {
                        matchModality = MatchModality.VIEW_PARTIAL;
                        ViewPartialRewriting partialRewritingResult = compensateViewPartial(call.builder(), rexBuilder, mq, view, topProject, node, queryTableRefs, qEC, topViewProject, viewNode, viewTableRefs);
                        if (partialRewritingResult == null) {
                            // Cannot rewrite, skip it
                            continue;
                        }
                        // Rewrite succeeded
                        view = partialRewritingResult.newView;
                        topViewProject = partialRewritingResult.newTopViewProject;
                        viewNode = partialRewritingResult.newViewNode;
                    } else {
                        // Skip it
                        continue;
                    }
                } else {
                    matchModality = MatchModality.COMPLETE;
                }
                // 4. We map every table in the query to a table with the same qualified
                // name (all query tables are contained in the view, thus this is equivalent
                // to mapping every table in the query to a view table).
                final Multimap<RelTableRef, RelTableRef> multiMapTables = ArrayListMultimap.create();
                for (RelTableRef queryTableRef1 : queryTableRefs) {
                    for (RelTableRef queryTableRef2 : queryTableRefs) {
                        if (queryTableRef1.getQualifiedName().equals(queryTableRef2.getQualifiedName())) {
                            multiMapTables.put(queryTableRef1, queryTableRef2);
                        }
                    }
                }
                // If a table is used multiple times, we will create multiple mappings,
                // and we will try to rewrite the query using each of the mappings.
                // Then, we will try to map every source table (query) to a target
                // table (view), and if we are successful, we will try to create
                // compensation predicates to filter the view results further
                // (if needed).
                final List<BiMap<RelTableRef, RelTableRef>> flatListMappings = generateTableMappings(multiMapTables);
                for (BiMap<RelTableRef, RelTableRef> queryToViewTableMapping : flatListMappings) {
                    // TableMapping : mapping query tables -> view tables
                    // 4.0. If compensation equivalence classes exist, we need to add
                    // the mapping to the query mapping
                    final EquivalenceClasses currQEC = EquivalenceClasses.copy(qEC);
                    if (matchModality == MatchModality.QUERY_PARTIAL) {
                        for (Entry<RexTableInputRef, RexTableInputRef> e : compensationEquiColumns.entries()) {
                            // Copy origin
                            RelTableRef queryTableRef = queryToViewTableMapping.inverse().get(e.getKey().getTableRef());
                            RexTableInputRef queryColumnRef = RexTableInputRef.of(queryTableRef, e.getKey().getIndex(), e.getKey().getType());
                            // Add to query equivalence classes and table mapping
                            currQEC.addEquivalenceClass(queryColumnRef, e.getValue());
                            queryToViewTableMapping.put(e.getValue().getTableRef(), // identity
                            e.getValue().getTableRef());
                        }
                    }
                    // 4.1. Compute compensation predicates, i.e., predicates that need to be
                    // enforced over the view to retain query semantics. The resulting predicates
                    // are expressed using {@link RexTableInputRef} over the query.
                    // First, to establish relationship, we swap column references of the view
                    // predicates to point to query tables and compute equivalence classes.
                    final RexNode viewColumnsEquiPred = RexUtil.swapTableReferences(rexBuilder, viewPreds.getLeft(), queryToViewTableMapping.inverse());
                    final EquivalenceClasses queryBasedVEC = new EquivalenceClasses();
                    for (RexNode conj : RelOptUtil.conjunctions(viewColumnsEquiPred)) {
                        assert conj.isA(SqlKind.EQUALS);
                        RexCall equiCond = (RexCall) conj;
                        queryBasedVEC.addEquivalenceClass((RexTableInputRef) equiCond.getOperands().get(0), (RexTableInputRef) equiCond.getOperands().get(1));
                    }
                    Triple<RexNode, RexNode, RexNode> compensationPreds = computeCompensationPredicates(rexBuilder, simplify, currQEC, queryPreds, queryBasedVEC, viewPreds, queryToViewTableMapping);
                    if (compensationPreds == null && generateUnionRewriting) {
                        // Attempt partial rewriting using union operator. This rewriting
                        // will read some data from the view and the rest of the data from
                        // the query computation. The resulting predicates are expressed
                        // using {@link RexTableInputRef} over the view.
                        compensationPreds = computeCompensationPredicates(rexBuilder, simplify, queryBasedVEC, viewPreds, currQEC, queryPreds, queryToViewTableMapping.inverse());
                        if (compensationPreds == null) {
                            // This was our last chance to use the view, skip it
                            continue;
                        }
                        RexNode compensationColumnsEquiPred = compensationPreds.getLeft();
                        RexNode otherCompensationPred = RexUtil.composeConjunction(rexBuilder, ImmutableList.of(compensationPreds.getMiddle(), compensationPreds.getRight()), false);
                        assert !compensationColumnsEquiPred.isAlwaysTrue() || !otherCompensationPred.isAlwaysTrue();
                        // b. Generate union branch (query).
                        final RelNode unionInputQuery = rewriteQuery(call.builder(), rexBuilder, simplify, mq, compensationColumnsEquiPred, otherCompensationPred, topProject, node, queryToViewTableMapping, queryBasedVEC, currQEC);
                        if (unionInputQuery == null) {
                            // Skip it
                            continue;
                        }
                        // c. Generate union branch (view).
                        // We trigger the unifying method. This method will either create a Project
                        // or an Aggregate operator on top of the view. It will also compute the
                        // output expressions for the query.
                        final RelNode unionInputView = rewriteView(call.builder(), rexBuilder, simplify, mq, matchModality, true, view, topProject, node, topViewProject, viewNode, queryToViewTableMapping, currQEC);
                        if (unionInputView == null) {
                            // Skip it
                            continue;
                        }
                        // d. Generate final rewriting (union).
                        final RelNode result = createUnion(call.builder(), rexBuilder, topProject, unionInputQuery, unionInputView);
                        if (result == null) {
                            // Skip it
                            continue;
                        }
                        call.transformTo(result);
                    } else if (compensationPreds != null) {
                        RexNode compensationColumnsEquiPred = compensationPreds.getLeft();
                        RexNode otherCompensationPred = RexUtil.composeConjunction(rexBuilder, ImmutableList.of(compensationPreds.getMiddle(), compensationPreds.getRight()), false);
                        // a. Compute final compensation predicate.
                        if (!compensationColumnsEquiPred.isAlwaysTrue() || !otherCompensationPred.isAlwaysTrue()) {
                            // All columns required by compensating predicates must be contained
                            // in the view output (condition 2).
                            List<RexNode> viewExprs = topViewProject == null ? extractReferences(rexBuilder, view) : topViewProject.getChildExps();
                            // since we want to enforce the rest
                            if (!compensationColumnsEquiPred.isAlwaysTrue()) {
                                compensationColumnsEquiPred = rewriteExpression(rexBuilder, mq, view, viewNode, viewExprs, queryToViewTableMapping.inverse(), queryBasedVEC, false, compensationColumnsEquiPred);
                                if (compensationColumnsEquiPred == null) {
                                    // Skip it
                                    continue;
                                }
                            }
                            // For the rest, we use the query equivalence classes
                            if (!otherCompensationPred.isAlwaysTrue()) {
                                otherCompensationPred = rewriteExpression(rexBuilder, mq, view, viewNode, viewExprs, queryToViewTableMapping.inverse(), currQEC, true, otherCompensationPred);
                                if (otherCompensationPred == null) {
                                    // Skip it
                                    continue;
                                }
                            }
                        }
                        final RexNode viewCompensationPred = RexUtil.composeConjunction(rexBuilder, ImmutableList.of(compensationColumnsEquiPred, otherCompensationPred), false);
                        // b. Generate final rewriting if possible.
                        // First, we add the compensation predicate (if any) on top of the view.
                        // Then, we trigger the unifying method. This method will either create a
                        // Project or an Aggregate operator on top of the view. It will also compute
                        // the output expressions for the query.
                        RelBuilder builder = call.builder();
                        RelNode viewWithFilter;
                        if (!viewCompensationPred.isAlwaysTrue()) {
                            RexNode newPred = simplify.simplify(viewCompensationPred);
                            viewWithFilter = builder.push(view).filter(newPred).build();
                            // We add (and push) the filter to the view plan before triggering the rewriting.
                            // This is useful in case some of the columns can be folded to same value after
                            // filter is added.
                            Pair<RelNode, RelNode> pushedNodes = pushFilterToOriginalViewPlan(builder, topViewProject, viewNode, newPred);
                            topViewProject = (Project) pushedNodes.left;
                            viewNode = pushedNodes.right;
                        } else {
                            viewWithFilter = builder.push(view).build();
                        }
                        final RelNode result = rewriteView(builder, rexBuilder, simplify, mq, matchModality, false, viewWithFilter, topProject, node, topViewProject, viewNode, queryToViewTableMapping, currQEC);
                        if (result == null) {
                            // Skip it
                            continue;
                        }
                        call.transformTo(result);
                    }
                // end else
                }
            }
        }
    }
}

Example 8 with Project

use of org.apache.calcite.rel.core.Project in project calcite by apache.

the class AggregateProjectMergeRule method onMatch.

public void onMatch(RelOptRuleCall call) {
    final Aggregate aggregate = call.rel(0);
    final Project project = call.rel(1);
    RelNode x = apply(call, aggregate, project);
    if (x != null) {
        call.transformTo(x);
    }
}

Example 9 with Project

use of org.apache.calcite.rel.core.Project in project calcite by apache.

the class JoinProjectTransposeRule method onMatch.

// ~ Methods ----------------------------------------------------------------
// implement RelOptRule
public void onMatch(RelOptRuleCall call) {
    Join joinRel = call.rel(0);
    JoinRelType joinType = joinRel.getJoinType();
    Project leftProj;
    Project rightProj;
    RelNode leftJoinChild;
    RelNode rightJoinChild;
    // 2) input's projection doesn't generate nulls
    if (hasLeftChild(call) && (includeOuter || !joinType.generatesNullsOnLeft())) {
        leftProj = call.rel(1);
        leftJoinChild = getProjectChild(call, leftProj, true);
    } else {
        leftProj = null;
        leftJoinChild = call.rel(1);
    }
    if (hasRightChild(call) && (includeOuter || !joinType.generatesNullsOnRight())) {
        rightProj = getRightChild(call);
        rightJoinChild = getProjectChild(call, rightProj, false);
    } else {
        rightProj = null;
        rightJoinChild = joinRel.getRight();
    }
    if ((leftProj == null) && (rightProj == null)) {
        return;
    }
    // Construct two RexPrograms and combine them.  The bottom program
    // is a join of the projection expressions from the left and/or
    // right projects that feed into the join.  The top program contains
    // the join condition.
    // Create a row type representing a concatenation of the inputs
    // underneath the projects that feed into the join.  This is the input
    // into the bottom RexProgram.  Note that the join type is an inner
    // join because the inputs haven't actually been joined yet.
    RelDataType joinChildrenRowType = SqlValidatorUtil.deriveJoinRowType(leftJoinChild.getRowType(), rightJoinChild.getRowType(), JoinRelType.INNER, joinRel.getCluster().getTypeFactory(), null, Collections.<RelDataTypeField>emptyList());
    // Create projection expressions, combining the projection expressions
    // from the projects that feed into the join.  For the RHS projection
    // expressions, shift them to the right by the number of fields on
    // the LHS.  If the join input was not a projection, simply create
    // references to the inputs.
    int nProjExprs = joinRel.getRowType().getFieldCount();
    final List<Pair<RexNode, String>> projects = new ArrayList<>();
    final RexBuilder rexBuilder = joinRel.getCluster().getRexBuilder();
    createProjectExprs(leftProj, leftJoinChild, 0, rexBuilder, joinChildrenRowType.getFieldList(), projects);
    List<RelDataTypeField> leftFields = leftJoinChild.getRowType().getFieldList();
    int nFieldsLeft = leftFields.size();
    createProjectExprs(rightProj, rightJoinChild, nFieldsLeft, rexBuilder, joinChildrenRowType.getFieldList(), projects);
    final List<RelDataType> projTypes = new ArrayList<>();
    for (int i = 0; i < nProjExprs; i++) {
        projTypes.add(projects.get(i).left.getType());
    }
    RelDataType projRowType = rexBuilder.getTypeFactory().createStructType(projTypes, Pair.right(projects));
    // create the RexPrograms and merge them
    RexProgram bottomProgram = RexProgram.create(joinChildrenRowType, Pair.left(projects), null, projRowType, rexBuilder);
    RexProgramBuilder topProgramBuilder = new RexProgramBuilder(projRowType, rexBuilder);
    topProgramBuilder.addIdentity();
    topProgramBuilder.addCondition(joinRel.getCondition());
    RexProgram topProgram = topProgramBuilder.getProgram();
    RexProgram mergedProgram = RexProgramBuilder.mergePrograms(topProgram, bottomProgram, rexBuilder);
    // expand out the join condition and construct a new LogicalJoin that
    // directly references the join children without the intervening
    // ProjectRels
    RexNode newCondition = mergedProgram.expandLocalRef(mergedProgram.getCondition());
    Join newJoinRel = joinRel.copy(joinRel.getTraitSet(), newCondition, leftJoinChild, rightJoinChild, joinRel.getJoinType(), joinRel.isSemiJoinDone());
    // expand out the new projection expressions; if the join is an
    // outer join, modify the expressions to reference the join output
    final List<RexNode> newProjExprs = new ArrayList<>();
    List<RexLocalRef> projList = mergedProgram.getProjectList();
    List<RelDataTypeField> newJoinFields = newJoinRel.getRowType().getFieldList();
    int nJoinFields = newJoinFields.size();
    int[] adjustments = new int[nJoinFields];
    for (int i = 0; i < nProjExprs; i++) {
        RexNode newExpr = mergedProgram.expandLocalRef(projList.get(i));
        if (joinType != JoinRelType.INNER) {
            newExpr = newExpr.accept(new RelOptUtil.RexInputConverter(rexBuilder, joinChildrenRowType.getFieldList(), newJoinFields, adjustments));
        }
        newProjExprs.add(newExpr);
    }
    // finally, create the projection on top of the join
    final RelBuilder relBuilder = call.builder();
    relBuilder.push(newJoinRel);
    relBuilder.project(newProjExprs, joinRel.getRowType().getFieldNames());
    // projection to fix differences wrt nullability of fields
    if (joinType != JoinRelType.INNER) {
        relBuilder.convert(joinRel.getRowType(), false);
    }
    call.transformTo(relBuilder.build());
}

Example 10 with Project

use of org.apache.calcite.rel.core.Project in project calcite by apache.

the class FilterProjectTransposeRule method onMatch.

// ~ Methods ----------------------------------------------------------------
public void onMatch(RelOptRuleCall call) {
    final Filter filter = call.rel(0);
    final Project project = call.rel(1);
    if (RexOver.containsOver(project.getProjects(), null)) {
        // it can be pushed down. For now we don't support this.
        return;
    }
    if (RexUtil.containsCorrelation(filter.getCondition())) {
        // Correlate from being de-correlated.
        return;
    }
    // convert the filter to one that references the child of the project
    RexNode newCondition = RelOptUtil.pushPastProject(filter.getCondition(), project);
    final RelBuilder relBuilder = call.builder();
    RelNode newFilterRel;
    if (copyFilter) {
        newFilterRel = filter.copy(filter.getTraitSet(), project.getInput(), RexUtil.removeNullabilityCast(relBuilder.getTypeFactory(), newCondition));
    } else {
        newFilterRel = relBuilder.push(project.getInput()).filter(newCondition).build();
    }
    RelNode newProjRel = copyProject ? project.copy(project.getTraitSet(), newFilterRel, project.getProjects(), project.getRowType()) : relBuilder.push(newFilterRel).project(project.getProjects(), project.getRowType().getFieldNames()).build();
    call.transformTo(newProjRel);
}