Examples with BeamPushDownIOSourceRel org.apache.beam.sdk.extensions.sql.impl.rel.BeamPushDownIOSourceRel used on opensource projects

Example 1 with BeamPushDownIOSourceRel

use of org.apache.beam.sdk.extensions.sql.impl.rel.BeamPushDownIOSourceRel in project beam by apache.

the class BeamIOPushDownRule method onMatch.

// ~ Methods ----------------------------------------------------------------
@Override
public void onMatch(RelOptRuleCall call) {
    final BeamIOSourceRel ioSourceRel = call.rel(1);
    final BeamSqlTable beamSqlTable = ioSourceRel.getBeamSqlTable();
    if (ioSourceRel instanceof BeamPushDownIOSourceRel) {
        return;
    }
    // Nested rows are not supported at the moment
    for (RelDataTypeField field : ioSourceRel.getRowType().getFieldList()) {
        if (field.getType() instanceof RelRecordType) {
            return;
        }
    }
    final Calc calc = call.rel(0);
    final RexProgram program = calc.getProgram();
    final Pair<ImmutableList<RexNode>, ImmutableList<RexNode>> projectFilter = program.split();
    final RelDataType calcInputRowType = program.getInputRowType();
    // When predicate push-down is not supported - all filters are unsupported.
    final BeamSqlTableFilter tableFilter = beamSqlTable.constructFilter(projectFilter.right);
    if (!beamSqlTable.supportsProjects().isSupported() && tableFilter instanceof DefaultTableFilter) {
        // Either project or filter push-down must be supported by the IO.
        return;
    }
    Set<String> usedFields = new LinkedHashSet<>();
    if (!(tableFilter instanceof DefaultTableFilter) && !beamSqlTable.supportsProjects().isSupported()) {
        // When applying standalone filter push-down all fields must be project by an IO.
        // With a single exception: Calc projects all fields (in the same order) and does nothing
        // else.
        usedFields.addAll(calcInputRowType.getFieldNames());
    } else {
        // Find all input refs used by projects
        for (RexNode project : projectFilter.left) {
            findUtilizedInputRefs(calcInputRowType, project, usedFields);
        }
        // Find all input refs used by filters
        for (RexNode filter : tableFilter.getNotSupported()) {
            findUtilizedInputRefs(calcInputRowType, filter, usedFields);
        }
    }
    if (usedFields.isEmpty()) {
        // No need to do push-down for queries like this: "select UPPER('hello')".
        return;
    }
    // IO only projects fields utilized by a calc.
    if (tableFilter.getNotSupported().containsAll(projectFilter.right) && usedFields.containsAll(ioSourceRel.getRowType().getFieldNames())) {
        return;
    }
    FieldAccessDescriptor resolved = FieldAccessDescriptor.withFieldNames(usedFields);
    resolved = resolved.resolve(beamSqlTable.getSchema());
    if (canDropCalc(program, beamSqlTable.supportsProjects(), tableFilter)) {
        call.transformTo(ioSourceRel.createPushDownRel(calc.getRowType(), resolved.getFieldsAccessed().stream().map(FieldDescriptor::getFieldName).collect(Collectors.toList()), tableFilter));
        return;
    }
    // IO only projects fields utilised by a calc.
    if (tableFilter.getNotSupported().equals(projectFilter.right) && usedFields.containsAll(ioSourceRel.getRowType().getFieldNames())) {
        return;
    }
    RelNode result = constructNodesWithPushDown(resolved, call.builder(), ioSourceRel, tableFilter, calc.getRowType(), projectFilter.left);
    if (tableFilter.getNotSupported().size() <= projectFilter.right.size() || usedFields.size() < calcInputRowType.getFieldCount()) {
        // Smaller Calc programs are indisputably better, as well as IOs with less projected fields.
        // We can consider something with the same number of filters.
        call.transformTo(result);
    }
}