Examples with ExpressionRef com.apple.foundationdb.record.query.plan.temp.ExpressionRef used on opensource projects

Example 11 with ExpressionRef

use of com.apple.foundationdb.record.query.plan.temp.ExpressionRef in project fdb-record-layer by FoundationDB.

the class AbstractDataAccessRule method onMatch.

/**
 * Method that does the leg work to create the appropriate expression dag for data access using value indexes or
 * value index-like scans (primary scans).
 *
 * Conceptually we do the following work:
 *
 * <ul>
 * <li> This method yields a scan plan for each matching primary candidate ({@link PrimaryScanMatchCandidate}).
 *      There is only ever going to be exactly one {@link PrimaryScanMatchCandidate} for a primary key. Due to the
 *      candidate being solely based upon a primary key, the match structure is somewhat limited. In essence, there
 *      is an implicit guarantee that we can always create a primary scan for a data source.
 * </li>
 * <li> This method yields an index scan plan for each matching value index candidate
 *      ({@link ValueIndexScanMatchCandidate}).
 * </li>
 * <li> This method yields the combinatorial expansion of intersections of distinct-ed index scan plans.
 * </li>
 * </ul>
 *
 * The work described above is semantically correct in a sense that it creates a search space that can be explored
 * and pruned in suitable ways that will eventually converge into an optimal data access plan.
 *
 * We can choose to create an index scan for every index that is available regardless what the coverage
 * of an index is. The coverage of an index is a measurement that tells us how well an index can answer what a
 * filter (or by extension a query) asks for. For instance, a high number of search arguments used in the index scan
 * can be associated with high coverage (as in the index scan covers more of the query) and vice versa.
 *
 * Similarly, we can choose to create the intersection of all possible combinations of suitable scans over indexes
 * (that we have matches for). Since we create a logical intersection of these access plans we can leave it up to
 * the respective implementation rules (e.g., {@link ImplementIntersectionRule}) to do the right thing and implement
 * the physical plan for the intersection if possible (e.g. ensuring compatibly ordered legs, etc.).
 *
 * In fact, the two before-mentioned approaches are completely valid with respect to correctness of the plan and
 * the guaranteed creation of the optimal plan. However, in reality using this approach, although valid and probably
 * the conceptually better and more orthogonal approach, will result in a ballooning of the search space very quickly.
 * While that may be acceptable for group-by engines and only few index access paths, in an OLTP world where there
 * are potentially dozens of indexes, memory footprint and the sheer number of tasks that would be created for
 * subsequent exploration and implementation of all these alternatives make the purist approach to planning these
 * indexes infeasible.
 *
 * Thus we would like to eliminate unnecessary exploration by avoiding variations we know can never be successful
 * either in creating a successful executable plan (e.g. logical expression may not ever be able to produce a
 * compatible ordering) or cannot ever create an optimal plan. In a nutshell, we try to utilize additional
 * information that is available in addition to the matching partition in order to make decisions about which
 * expression variation to create and which to avoid:
 *
 * <ul>
 * <li> For a matching primary scan candidate ({@link PrimaryScanMatchCandidate})
 *      we will not create a primary scan if the scan is incompatible with an interesting order that has been
 *      communicated downwards in the graph.
 * </li>
 * <li> For a matching index scan candidate ({@link ValueIndexScanMatchCandidate})
 *      we will not create an index scan if the scan is incompatible with an interesting order that has been
 *      communicated downwards in the graph.
 * </li>
 * <li> We will only create a scan if there is no other index scan with a greater coverage (think of coverage
 *      as the assumed amount of filtering or currently the number of bound predicates) for the search arguments
 *      which are bound by the query.
 *      For instance, an index scan {@code INDEX SCAN(i1, a = [5, 5], b = [10, 10])} is still planned along
 *      {@code INDEX SCAN(i2, x = ["hello", "hello"], y = ["world", "world"], z = [10, inf])} even though
 *      the latter utilizes three search arguments while the former one only uses two. However, an index scan
 *      {@code INDEX SCAN(i1, a = [5, 5], b = [10, 10])} is not created (and yielded) if there we also
 *      have a choice to plan {@code INDEX SCAN(i2, b = [10, 10], a = [5, 5], c = ["Guten", "Morgen"])} as that
 *      index {@code i2} has a higher coverage compared to {@code i1} <em>and</em> all bound arguments in the scan
 *      over {@code i2} are also bound in the scan over {@code i1}.
 * <li>
 *      We will only create intersections of scans if we can already establish that the logical intersection
 *      can be implemented by a {@link com.apple.foundationdb.record.query.plan.plans.RecordQueryIntersectionPlan}.
 *      That requires that the legs of the intersection are compatibly ordered <em>and</em> that that ordering follows
 *      a potentially required ordering.
 * </li>
 * </ul>
 *
 * @param call the call associated with this planner rule execution
 */
@Override
@SuppressWarnings("java:S135")
public void onMatch(@Nonnull PlannerRuleCall call) {
    final PlannerBindings bindings = call.getBindings();
    final List<? extends PartialMatch> completeMatches = bindings.getAll(getCompleteMatchMatcher());
    final R expression = bindings.get(getExpressionMatcher());
    // 
    if (completeMatches.isEmpty()) {
        return;
    }
    // 
    // return if there is no pre-determined interesting ordering
    // 
    final Optional<Set<RequestedOrdering>> requestedOrderingsOptional = call.getInterestingProperty(OrderingAttribute.ORDERING);
    if (requestedOrderingsOptional.isEmpty()) {
        return;
    }
    final Set<RequestedOrdering> requestedOrderings = requestedOrderingsOptional.get();
    // 
    // group matches by candidates
    // 
    final LinkedHashMap<MatchCandidate, ? extends ImmutableList<? extends PartialMatch>> completeMatchMap = completeMatches.stream().collect(Collectors.groupingBy(PartialMatch::getMatchCandidate, LinkedHashMap::new, ImmutableList.toImmutableList()));
    // find the best match for a candidate as there may be more than one due to partial matching
    final ImmutableSet<PartialMatch> maximumCoverageMatchPerCandidate = completeMatchMap.entrySet().stream().flatMap(entry -> {
        final List<? extends PartialMatch> completeMatchesForCandidate = entry.getValue();
        final Optional<? extends PartialMatch> bestMatchForCandidateOptional = completeMatchesForCandidate.stream().max(Comparator.comparing(PartialMatch::getNumBoundParameterPrefix));
        return bestMatchForCandidateOptional.map(Stream::of).orElse(Stream.empty());
    }).collect(ImmutableSet.toImmutableSet());
    final List<PartialMatch> bestMaximumCoverageMatches = maximumCoverageMatches(maximumCoverageMatchPerCandidate, requestedOrderings);
    if (bestMaximumCoverageMatches.isEmpty()) {
        return;
    }
    // create scans for all best matches
    final Map<PartialMatch, RelationalExpression> bestMatchToExpressionMap = createScansForMatches(bestMaximumCoverageMatches);
    final ExpressionRef<RelationalExpression> toBeInjectedReference = GroupExpressionRef.empty();
    // create single scan accesses
    for (final PartialMatch bestMatch : bestMaximumCoverageMatches) {
        final RelationalExpression dataAccessAndCompensationExpression = compensateSingleDataAccess(bestMatch, bestMatchToExpressionMap.get(bestMatch));
        toBeInjectedReference.insert(dataAccessAndCompensationExpression);
    }
    final Map<PartialMatch, RelationalExpression> bestMatchToDistinctExpressionMap = distinctMatchToScanMap(bestMatchToExpressionMap);
    @Nullable final KeyExpression commonPrimaryKey = call.getContext().getCommonPrimaryKey();
    if (commonPrimaryKey != null) {
        final var commonPrimaryKeyParts = commonPrimaryKey.normalizeKeyForPositions();
        final var boundPartitions = Lists.<List<PartialMatch>>newArrayList();
        // create intersections for all n choose k partitions from k = 2 .. n
        IntStream.range(2, bestMaximumCoverageMatches.size() + 1).mapToObj(k -> ChooseK.chooseK(bestMaximumCoverageMatches, k)).flatMap(iterable -> StreamSupport.stream(iterable.spliterator(), false)).forEach(boundPartitions::add);
        boundPartitions.stream().flatMap(partition -> createIntersectionAndCompensation(commonPrimaryKeyParts, bestMatchToDistinctExpressionMap, partition, requestedOrderings).stream()).forEach(toBeInjectedReference::insert);
    }
    call.yield(inject(expression, completeMatches, toBeInjectedReference));
}

Example 12 with ExpressionRef

use of com.apple.foundationdb.record.query.plan.temp.ExpressionRef in project fdb-record-layer by FoundationDB.

the class PushSetOperationThroughFetchRule method onMatch.

@Override
@SuppressWarnings("java:S1905")
public void onMatch(@Nonnull PlannerRuleCall call) {
    final PlannerBindings bindings = call.getBindings();
    final RecordQuerySetPlan setOperationPlan = bindings.get(getMatcher());
    final List<? extends Quantifier.Physical> quantifiersOverFetches = bindings.getAll(quantifierOverFetchMatcher);
    // if set operation is dynamic all quantifiers must have fetches
    if (setOperationPlan.isDynamic()) {
        if (quantifiersOverFetches.size() < setOperationPlan.getQuantifiers().size()) {
            return;
        }
    } else {
        if (quantifiersOverFetches.size() <= 1) {
            // pulling up the fetch is meaningless in this case
            return;
        }
    }
    final List<? extends RecordQueryFetchFromPartialRecordPlan> fetchPlans = bindings.getAll(fetchPlanMatcher);
    final ImmutableList<TranslateValueFunction> dependentFunctions = fetchPlans.stream().map(RecordQueryFetchFromPartialRecordPlan::getPushValueFunction).collect(ImmutableList.toImmutableList());
    Verify.verify(quantifiersOverFetches.size() == fetchPlans.size());
    Verify.verify(fetchPlans.size() == dependentFunctions.size());
    final List<? extends Value> requiredValues = setOperationPlan.getRequiredValues(CorrelationIdentifier.uniqueID());
    final Set<CorrelationIdentifier> pushableAliases = setOperationPlan.tryPushValues(dependentFunctions, quantifiersOverFetches, requiredValues);
    // if set operation is dynamic all aliases must be pushable
    if (setOperationPlan.isDynamic()) {
        if (pushableAliases.size() < setOperationPlan.getQuantifiers().size()) {
            return;
        }
    } else {
        if (pushableAliases.size() <= 1) {
            // pulling up the fetch is meaningless in this case
            return;
        }
    }
    final ImmutableList.Builder<Quantifier.Physical> pushableQuantifiersBuilder = ImmutableList.builder();
    final ImmutableList.Builder<RecordQueryFetchFromPartialRecordPlan> pushableFetchPlansBuilder = ImmutableList.builder();
    final ImmutableList.Builder<TranslateValueFunction> pushableDependentFunctionsBuilder = ImmutableList.builder();
    for (int i = 0; i < quantifiersOverFetches.size(); i++) {
        final Quantifier.Physical quantifier = quantifiersOverFetches.get(i);
        if (pushableAliases.contains(quantifier.getAlias())) {
            pushableQuantifiersBuilder.add(quantifier);
            pushableFetchPlansBuilder.add(fetchPlans.get(i));
            pushableDependentFunctionsBuilder.add(dependentFunctions.get(i));
        }
    }
    final ImmutableList<Quantifier.Physical> pushableQuantifiers = pushableQuantifiersBuilder.build();
    final ImmutableList<RecordQueryFetchFromPartialRecordPlan> pushableFetchPlans = pushableFetchPlansBuilder.build();
    final ImmutableList<TranslateValueFunction> pushableDependentFunctions = pushableDependentFunctionsBuilder.build();
    final ImmutableList<Quantifier.Physical> nonPushableQuantifiers = setOperationPlan.getQuantifiers().stream().map(quantifier -> (Quantifier.Physical) quantifier).filter(quantifier -> !pushableAliases.contains(quantifier.getAlias())).collect(ImmutableList.toImmutableList());
    final List<? extends ExpressionRef<RecordQueryPlan>> newPushedInnerPlans = pushableFetchPlans.stream().map(RecordQueryFetchFromPartialRecordPlan::getChild).map(GroupExpressionRef::of).collect(ImmutableList.toImmutableList());
    Verify.verify(pushableQuantifiers.size() + nonPushableQuantifiers.size() == setOperationPlan.getQuantifiers().size());
    final TranslateValueFunction combinedTranslateValueFunction = setOperationPlan.pushValueFunction(pushableDependentFunctions);
    final RecordQuerySetPlan newSetOperationPlan = setOperationPlan.withChildrenReferences(newPushedInnerPlans);
    final RecordQueryFetchFromPartialRecordPlan newFetchPlan = new RecordQueryFetchFromPartialRecordPlan(newSetOperationPlan, combinedTranslateValueFunction);
    if (nonPushableQuantifiers.isEmpty()) {
        call.yield(GroupExpressionRef.of(newFetchPlan));
    } else {
        final List<ExpressionRef<? extends RecordQueryPlan>> newFetchPlanAndResidualInners = Streams.concat(Stream.of(GroupExpressionRef.of(newFetchPlan)), nonPushableQuantifiers.stream().map(Quantifier.Physical::getRangesOver).map(RecordQueryPlan::narrowReference)).collect(ImmutableList.toImmutableList());
        call.yield(GroupExpressionRef.of(setOperationPlan.withChildrenReferences(newFetchPlanAndResidualInners)));
    }
}

Example 13 with ExpressionRef

use of com.apple.foundationdb.record.query.plan.temp.ExpressionRef in project fdb-record-layer by FoundationDB.

the class PushTypeFilterBelowFilterRule method onMatch.

@Override
public void onMatch(@Nonnull PlannerRuleCall call) {
    final PlannerBindings bindings = call.getBindings();
    final ExpressionRef<? extends RelationalExpression> inner = bindings.get(innerMatcher);
    final Quantifier.Physical qun = bindings.get(qunMatcher);
    final List<? extends QueryPredicate> predicates = bindings.getAll(predMatcher);
    final Collection<String> recordTypes = bindings.get(root).getRecordTypes();
    final RecordQueryTypeFilterPlan newTypeFilterPlan = new RecordQueryTypeFilterPlan(Quantifier.physical(inner), recordTypes);
    final Quantifier.Physical newQun = Quantifier.physical(call.ref(newTypeFilterPlan));
    final List<QueryPredicate> rebasedPredicates = predicates.stream().map(queryPredicate -> queryPredicate.rebase(Quantifiers.translate(qun, newQun))).collect(ImmutableList.toImmutableList());
    call.yield(GroupExpressionRef.of(new RecordQueryPredicatesFilterPlan(newQun, rebasedPredicates)));
}

Example 14 with ExpressionRef

use of com.apple.foundationdb.record.query.plan.temp.ExpressionRef in project fdb-record-layer by FoundationDB.

the class MatchIntermediateRule method onMatch.

@Override
public void onMatch(@Nonnull PlannerRuleCall call) {
    final PlannerBindings bindings = call.getBindings();
    final RelationalExpression expression = bindings.get(root);
    final List<? extends Quantifier> quantifiers = bindings.getAll(quantifierMatcher);
    final ImmutableList<? extends ExpressionRef<? extends RelationalExpression>> rangesOverRefs = quantifiers.stream().map(Quantifier::getRangesOver).collect(ImmutableList.toImmutableList());
    // form union of all possible match candidates that this rule application should look at
    final Set<MatchCandidate> childMatchCandidates = new LinkedIdentitySet<>();
    for (int i = 0; i < rangesOverRefs.size(); i++) {
        final ExpressionRef<? extends RelationalExpression> rangesOverGroup = rangesOverRefs.get(i);
        childMatchCandidates.addAll(rangesOverGroup.getMatchCandidates());
    }
    // go through all match candidates
    for (final MatchCandidate matchCandidate : childMatchCandidates) {
        final SetMultimap<ExpressionRef<? extends RelationalExpression>, RelationalExpression> refToExpressionMap = matchCandidate.findReferencingExpressions(rangesOverRefs);
        // go through all reference paths, i.e., (ref, expression) pairs
        for (final Map.Entry<ExpressionRef<? extends RelationalExpression>, RelationalExpression> entry : refToExpressionMap.entries()) {
            final ExpressionRef<? extends RelationalExpression> candidateReference = entry.getKey();
            final RelationalExpression candidateExpression = entry.getValue();
            // match this expression with the candidate expression and yield zero to n new partial matches
            final Iterable<BoundMatch<MatchInfo>> boundMatchInfos = matchWithCandidate(expression, matchCandidate, candidateExpression);
            boundMatchInfos.forEach(boundMatchInfo -> call.yieldPartialMatch(boundMatchInfo.getAliasMap(), matchCandidate, expression, candidateReference, boundMatchInfo.getMatchResult()));
        }
    }
}

Example 15 with ExpressionRef

use of com.apple.foundationdb.record.query.plan.temp.ExpressionRef in project fdb-record-layer by FoundationDB.

the class MatchLeafRule method onMatch.

@Override
public void onMatch(@Nonnull PlannerRuleCall call) {
    final PlanContext context = call.getContext();
    final RelationalExpression expression = call.get(root);
    // iterate through all candidates known to the context
    for (final MatchCandidate matchCandidate : context.getMatchCandidates()) {
        final ExpressionRefTraversal traversal = matchCandidate.getTraversal();
        final Set<ExpressionRef<? extends RelationalExpression>> leafRefs = traversal.getLeafReferences();
        // iterate through all leaf references in all
        for (final ExpressionRef<? extends RelationalExpression> leafRef : leafRefs) {
            for (final RelationalExpression leafMember : leafRef.getMembers()) {
                // expressions.
                if (leafMember.getQuantifiers().isEmpty()) {
                    final Iterable<BoundMatch<MatchInfo>> boundMatchInfos = matchWithCandidate(expression, leafMember);
                    // yield any match to the planner
                    boundMatchInfos.forEach(boundMatchInfo -> call.yieldPartialMatch(boundMatchInfo.getAliasMap(), matchCandidate, expression, leafRef, boundMatchInfo.getMatchResult()));
                }
            }
        }
    }
}