Examples with DruidJoinQueryRel org.apache.druid.sql.calcite.rel.DruidJoinQueryRel used on opensource projects

Example 1 with DruidJoinQueryRel

use of org.apache.druid.sql.calcite.rel.DruidJoinQueryRel in project druid by druid-io.

the class DruidJoinRule method onMatch.

@Override
public void onMatch(RelOptRuleCall call) {
    final Join join = call.rel(0);
    final DruidRel<?> left = call.rel(1);
    final DruidRel<?> right = call.rel(2);
    final RexBuilder rexBuilder = join.getCluster().getRexBuilder();
    final DruidRel<?> newLeft;
    final DruidRel<?> newRight;
    final Filter leftFilter;
    final List<RexNode> newProjectExprs = new ArrayList<>();
    // Already verified to be present in "matches", so just call "get".
    // Can't be final, because we're going to reassign it up to a couple of times.
    ConditionAnalysis conditionAnalysis = analyzeCondition(join.getCondition(), join.getLeft().getRowType(), right).get();
    final boolean isLeftDirectAccessPossible = enableLeftScanDirect && (left instanceof DruidQueryRel);
    if (left.getPartialDruidQuery().stage() == PartialDruidQuery.Stage.SELECT_PROJECT && (isLeftDirectAccessPossible || left.getPartialDruidQuery().getWhereFilter() == null)) {
        // Swap the left-side projection above the join, so the left side is a simple scan or mapping. This helps us
        // avoid subqueries.
        final RelNode leftScan = left.getPartialDruidQuery().getScan();
        final Project leftProject = left.getPartialDruidQuery().getSelectProject();
        leftFilter = left.getPartialDruidQuery().getWhereFilter();
        // Left-side projection expressions rewritten to be on top of the join.
        newProjectExprs.addAll(leftProject.getProjects());
        newLeft = left.withPartialQuery(PartialDruidQuery.create(leftScan));
        conditionAnalysis = conditionAnalysis.pushThroughLeftProject(leftProject);
    } else {
        // Leave left as-is. Write input refs that do nothing.
        for (int i = 0; i < left.getRowType().getFieldCount(); i++) {
            newProjectExprs.add(rexBuilder.makeInputRef(join.getRowType().getFieldList().get(i).getType(), i));
        }
        newLeft = left;
        leftFilter = null;
    }
    if (right.getPartialDruidQuery().stage() == PartialDruidQuery.Stage.SELECT_PROJECT && right.getPartialDruidQuery().getWhereFilter() == null && !right.getPartialDruidQuery().getSelectProject().isMapping() && conditionAnalysis.onlyUsesMappingsFromRightProject(right.getPartialDruidQuery().getSelectProject())) {
        // Swap the right-side projection above the join, so the right side is a simple scan or mapping. This helps us
        // avoid subqueries.
        final RelNode rightScan = right.getPartialDruidQuery().getScan();
        final Project rightProject = right.getPartialDruidQuery().getSelectProject();
        // Right-side projection expressions rewritten to be on top of the join.
        for (final RexNode rexNode : RexUtil.shift(rightProject.getProjects(), newLeft.getRowType().getFieldCount())) {
            if (join.getJoinType().generatesNullsOnRight()) {
                newProjectExprs.add(makeNullableIfLiteral(rexNode, rexBuilder));
            } else {
                newProjectExprs.add(rexNode);
            }
        }
        newRight = right.withPartialQuery(PartialDruidQuery.create(rightScan));
        conditionAnalysis = conditionAnalysis.pushThroughRightProject(rightProject);
    } else {
        // Leave right as-is. Write input refs that do nothing.
        for (int i = 0; i < right.getRowType().getFieldCount(); i++) {
            newProjectExprs.add(rexBuilder.makeInputRef(join.getRowType().getFieldList().get(left.getRowType().getFieldCount() + i).getType(), newLeft.getRowType().getFieldCount() + i));
        }
        newRight = right;
    }
    // Druid join written on top of the new left and right sides.
    final DruidJoinQueryRel druidJoin = DruidJoinQueryRel.create(join.copy(join.getTraitSet(), conditionAnalysis.getCondition(rexBuilder), newLeft, newRight, join.getJoinType(), join.isSemiJoinDone()), leftFilter, left.getPlannerContext());
    final RelBuilder relBuilder = call.builder().push(druidJoin).project(RexUtil.fixUp(rexBuilder, newProjectExprs, RelOptUtil.getFieldTypeList(druidJoin.getRowType())));
    call.transformTo(relBuilder.build());
}