Examples with CommonRelSubExprRule org.apache.calcite.plan.CommonRelSubExprRule used on opensource projects

Example 1 with CommonRelSubExprRule

use of org.apache.calcite.plan.CommonRelSubExprRule in project calcite by apache.

the class HepPlanner method applyRule.

private HepRelVertex applyRule(RelOptRule rule, HepRelVertex vertex, boolean forceConversions) {
    if (!belongsToDag(vertex)) {
        return null;
    }
    RelTrait parentTrait = null;
    List<RelNode> parents = null;
    if (rule instanceof ConverterRule) {
        // Guaranteed converter rules require special casing to make sure
        // they only fire where actually needed, otherwise they tend to
        // fire to infinity and beyond.
        ConverterRule converterRule = (ConverterRule) rule;
        if (converterRule.isGuaranteed() || !forceConversions) {
            if (!doesConverterApply(converterRule, vertex)) {
                return null;
            }
            parentTrait = converterRule.getOutTrait();
        }
    } else if (rule instanceof CommonRelSubExprRule) {
        // Only fire CommonRelSubExprRules if the vertex is a common
        // subexpression.
        List<HepRelVertex> parentVertices = getVertexParents(vertex);
        if (parentVertices.size() < 2) {
            return null;
        }
        parents = new ArrayList<>();
        for (HepRelVertex pVertex : parentVertices) {
            parents.add(pVertex.getCurrentRel());
        }
    }
    final List<RelNode> bindings = new ArrayList<>();
    final Map<RelNode, List<RelNode>> nodeChildren = new HashMap<>();
    boolean match = matchOperands(rule.getOperand(), vertex.getCurrentRel(), bindings, nodeChildren);
    if (!match) {
        return null;
    }
    HepRuleCall call = new HepRuleCall(this, rule.getOperand(), bindings.toArray(new RelNode[bindings.size()]), nodeChildren, parents);
    // Allow the rule to apply its own side-conditions.
    if (!rule.matches(call)) {
        return null;
    }
    fireRule(call);
    if (!call.getResults().isEmpty()) {
        return applyTransformationResults(vertex, call, parentTrait);
    }
    return null;
}