예제 #1
0
 /**
  * Return true if 'this' and other have compatible partition exprs and our orderByElements are a
  * prefix of other's.
  */
 public boolean isPrefixOf(SortGroup other) {
   if (other.orderByElements.size() > orderByElements.size()) return false;
   if (!Expr.equalSets(partitionByExprs, other.partitionByExprs)) return false;
   for (int i = 0; i < other.orderByElements.size(); ++i) {
     OrderByElement ob = orderByElements.get(i);
     OrderByElement otherOb = other.orderByElements.get(i);
     // TODO: compare equiv classes by comparing each equiv class's placeholder
     // slotref
     if (!ob.getExpr().equals(otherOb.getExpr())) return false;
     if (ob.isAsc() != otherOb.isAsc()) return false;
     if (ob.nullsFirst() != otherOb.nullsFirst()) return false;
   }
   return true;
 }
예제 #2
0
  /**
   * Create plan tree for the entire sort group, including all contained window groups. Marks the
   * SortNode as requiring its input to be partitioned if partitionExprs is not null (partitionExprs
   * represent the data partition of the entire partition group of which this sort group is a part).
   */
  private PlanNode createSortGroupPlan(
      PlanNode root, SortGroup sortGroup, List<Expr> partitionExprs) throws ImpalaException {
    List<Expr> partitionByExprs = sortGroup.partitionByExprs;
    List<OrderByElement> orderByElements = sortGroup.orderByElements;
    ExprSubstitutionMap sortSmap = null;
    TupleId sortTupleId = null;
    TupleDescriptor bufferedTupleDesc = null;
    // map from input to buffered tuple
    ExprSubstitutionMap bufferedSmap = new ExprSubstitutionMap();

    // sort on partition by (pb) + order by (ob) exprs and create pb/ob predicates
    if (!partitionByExprs.isEmpty() || !orderByElements.isEmpty()) {
      // first sort on partitionExprs (direction doesn't matter)
      List<Expr> sortExprs = Lists.newArrayList(partitionByExprs);
      List<Boolean> isAsc =
          Lists.newArrayList(Collections.nCopies(sortExprs.size(), new Boolean(true)));
      // TODO: utilize a direction and nulls/first last that has benefit
      // for subsequent sort groups
      List<Boolean> nullsFirst =
          Lists.newArrayList(Collections.nCopies(sortExprs.size(), new Boolean(true)));

      // then sort on orderByExprs
      for (OrderByElement orderByElement : sortGroup.orderByElements) {
        sortExprs.add(orderByElement.getExpr());
        isAsc.add(orderByElement.isAsc());
        nullsFirst.add(orderByElement.getNullsFirstParam());
      }

      SortInfo sortInfo = createSortInfo(root, sortExprs, isAsc, nullsFirst);
      SortNode sortNode = new SortNode(idGenerator_.getNextId(), root, sortInfo, false, 0);

      // if this sort group does not have partitioning exprs, we want the sort
      // to be executed like a regular distributed sort
      if (!partitionByExprs.isEmpty()) sortNode.setIsAnalyticSort(true);

      if (partitionExprs != null) {
        // create required input partition
        DataPartition inputPartition = DataPartition.UNPARTITIONED;
        if (!partitionExprs.isEmpty()) {
          inputPartition = new DataPartition(TPartitionType.HASH_PARTITIONED, partitionExprs);
        }
        sortNode.setInputPartition(inputPartition);
      }

      root = sortNode;
      root.init(analyzer_);
      sortSmap = sortNode.getOutputSmap();

      // create bufferedTupleDesc and bufferedSmap
      sortTupleId = sortNode.tupleIds_.get(0);
      bufferedTupleDesc = analyzer_.getDescTbl().copyTupleDescriptor(sortTupleId, "buffered-tuple");
      LOG.trace("desctbl: " + analyzer_.getDescTbl().debugString());

      List<SlotDescriptor> inputSlots = analyzer_.getTupleDesc(sortTupleId).getSlots();
      List<SlotDescriptor> bufferedSlots = bufferedTupleDesc.getSlots();
      for (int i = 0; i < inputSlots.size(); ++i) {
        bufferedSmap.put(new SlotRef(inputSlots.get(i)), new SlotRef(bufferedSlots.get(i)));
      }
    }

    // create one AnalyticEvalNode per window group
    for (WindowGroup windowGroup : sortGroup.windowGroups) {
      // Create partition-by (pb) and order-by (ob) less-than predicates between the
      // input tuple (the output of the preceding sort) and a buffered tuple that is
      // identical to the input tuple. We need a different tuple descriptor for the
      // buffered tuple because the generated predicates should compare two different
      // tuple instances from the same input stream (i.e., the predicates should be
      // evaluated over a row that is composed of the input and the buffered tuple).

      // we need to remap the pb/ob exprs to a) the sort output, b) our buffer of the
      // sort input
      Expr partitionByEq = null;
      if (!windowGroup.partitionByExprs.isEmpty()) {
        partitionByEq =
            createNullMatchingEquals(
                Expr.substituteList(windowGroup.partitionByExprs, sortSmap, analyzer_, false),
                sortTupleId,
                bufferedSmap);
        LOG.trace("partitionByEq: " + partitionByEq.debugString());
      }
      Expr orderByEq = null;
      if (!windowGroup.orderByElements.isEmpty()) {
        orderByEq =
            createNullMatchingEquals(
                OrderByElement.getOrderByExprs(
                    OrderByElement.substitute(windowGroup.orderByElements, sortSmap, analyzer_)),
                sortTupleId,
                bufferedSmap);
        LOG.trace("orderByEq: " + orderByEq.debugString());
      }

      root =
          new AnalyticEvalNode(
              idGenerator_.getNextId(),
              root,
              stmtTupleIds_,
              windowGroup.analyticFnCalls,
              windowGroup.partitionByExprs,
              windowGroup.orderByElements,
              windowGroup.window,
              analyticInfo_.getOutputTupleDesc(),
              windowGroup.physicalIntermediateTuple,
              windowGroup.physicalOutputTuple,
              windowGroup.logicalToPhysicalSmap,
              partitionByEq,
              orderByEq,
              bufferedTupleDesc);
      root.init(analyzer_);
    }
    return root;
  }