Examples with DrillLimitRel org.apache.drill.exec.planner.logical.DrillLimitRel used on opensource projects

Example 1 with DrillLimitRel

use of org.apache.drill.exec.planner.logical.DrillLimitRel in project drill by axbaretto.

the class LimitPrule method onMatch.

@Override
public void onMatch(RelOptRuleCall call) {
    final DrillLimitRel limit = (DrillLimitRel) call.rel(0);
    final RelNode input = limit.getInput();
    final RelTraitSet traits = input.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.SINGLETON);
    final RelNode convertedInput = convert(input, traits);
    LimitPrel newLimit = new LimitPrel(limit.getCluster(), limit.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.SINGLETON), convertedInput, limit.getOffset(), limit.getFetch());
    call.transformTo(newLimit);
}

Example 2 with DrillLimitRel

use of org.apache.drill.exec.planner.logical.DrillLimitRel in project drill by apache.

the class JoinUtils method isScalarSubquery.

/**
 * Utility method to check if a subquery (represented by its root RelNode) is provably scalar. Currently
 * only aggregates with no group-by are considered scalar. In the future, this method should be generalized
 * to include more cases and reconciled with Calcite's notion of scalar.
 * @param root The root RelNode to be examined
 * @return True if the root rel or its descendant is scalar, False otherwise
 */
public static boolean isScalarSubquery(RelNode root) {
    DrillAggregateRel agg = null;
    RelNode currentrel = root;
    while (agg == null && currentrel != null) {
        if (currentrel instanceof DrillAggregateRel) {
            agg = (DrillAggregateRel) currentrel;
        } else if (currentrel instanceof RelSubset) {
            currentrel = ((RelSubset) currentrel).getBest();
        } else if (currentrel instanceof DrillLimitRel) {
            // TODO: Improve this check when DRILL-5691 is fixed.
            // The problem is that RelMdMaxRowCount currently cannot be used
            // due to CALCITE-1048.
            Integer fetchValue = ((RexLiteral) ((DrillLimitRel) currentrel).getFetch()).getValueAs(Integer.class);
            return fetchValue != null && fetchValue <= 1;
        } else if (currentrel.getInputs().size() == 1) {
            // If the rel is not an aggregate or RelSubset, but is a single-input rel (could be Project,
            // Filter, Sort etc.), check its input
            currentrel = currentrel.getInput(0);
        } else {
            break;
        }
    }
    if (agg != null) {
        if (agg.getGroupSet().isEmpty()) {
            return true;
        }
        // with empty call list and literal from project expression in group set.
        if (agg.getAggCallList().isEmpty() && agg.getGroupSet().cardinality() == 1) {
            ProjectExpressionsCollector expressionsCollector = new ProjectExpressionsCollector();
            agg.accept(expressionsCollector);
            List<RexNode> projectedExpressions = expressionsCollector.getProjectedExpressions();
            return projectedExpressions.size() == 1 && RexUtil.isLiteral(projectedExpressions.get(agg.getGroupSet().nth(0)), true);
        }
    }
    return false;
}

Example 3 with DrillLimitRel

use of org.apache.drill.exec.planner.logical.DrillLimitRel in project drill by apache.

the class LimitPrule method onMatch.

@Override
public void onMatch(RelOptRuleCall call) {
    final DrillLimitRel limit = (DrillLimitRel) call.rel(0);
    final RelNode input = limit.getInput();
    final RelTraitSet traits = input.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.SINGLETON);
    final RelNode convertedInput = convert(input, traits);
    LimitPrel newLimit = new LimitPrel(limit.getCluster(), limit.getTraitSet().plus(Prel.DRILL_PHYSICAL).plus(DrillDistributionTrait.SINGLETON), convertedInput, limit.getOffset(), limit.getFetch());
    call.transformTo(newLimit);
}

Example 4 with DrillLimitRel

use of org.apache.drill.exec.planner.logical.DrillLimitRel in project drill by apache.

the class FindLimit0Visitor method addLimitOnTopOfLeafNodes.

public static DrillRel addLimitOnTopOfLeafNodes(final DrillRel rel) {
    final Pointer<Boolean> isUnsupported = new Pointer<>(false);
    // to visit unsupported functions
    final RexShuttle unsupportedFunctionsVisitor = new RexShuttle() {

        @Override
        public RexNode visitCall(RexCall call) {
            final SqlOperator operator = call.getOperator();
            if (isUnsupportedScalarFunction(operator)) {
                isUnsupported.value = true;
                return call;
            }
            return super.visitCall(call);
        }
    };
    // to visit unsupported operators
    final RelShuttle unsupportedOperationsVisitor = new RelShuttleImpl() {

        @Override
        public RelNode visit(RelNode other) {
            if (other instanceof DrillUnionRelBase) {
                isUnsupported.value = true;
                return other;
            } else if (other instanceof DrillProjectRelBase) {
                if (!isUnsupported.value) {
                    other.accept(unsupportedFunctionsVisitor);
                }
                if (isUnsupported.value) {
                    return other;
                }
            }
            return super.visit(other);
        }
    };
    rel.accept(unsupportedOperationsVisitor);
    if (isUnsupported.value) {
        return rel;
    }
    // to add LIMIT (0) on top of leaf nodes
    final RelShuttle addLimitOnScanVisitor = new RelShuttleImpl() {

        private RelNode addLimitAsParent(RelNode node) {
            final RexBuilder builder = node.getCluster().getRexBuilder();
            final RexLiteral offset = builder.makeExactLiteral(BigDecimal.ZERO);
            final RexLiteral fetch = builder.makeExactLiteral(BigDecimal.ZERO);
            return new DrillLimitRel(node.getCluster(), node.getTraitSet(), node, offset, fetch);
        }

        @Override
        public RelNode visit(LogicalValues values) {
            return addLimitAsParent(values);
        }

        @Override
        public RelNode visit(TableScan scan) {
            return addLimitAsParent(scan);
        }

        @Override
        public RelNode visit(RelNode other) {
            if (other.getInputs().isEmpty()) {
                // leaf operator
                return addLimitAsParent(other);
            }
            return super.visit(other);
        }
    };
    return (DrillRel) rel.accept(addLimitOnScanVisitor);
}