Examples of org.apache.tajo.engine.planner.logical.RelationNode

    // initialize a relation set
    HashMap<String, RelationNode> relationMap = Maps.newHashMap();
    // Remain relation set to be joined
    Set<String> remainRelNames = new HashSet<String>();
    for (RelationNode relation : block.getRelations()) {
      RelationNode rel = relation;
      relationMap.put(rel.getCanonicalName(), rel);
      remainRelNames.add(rel.getCanonicalName());
    }
    // A set of already-joined relations
    Set<String> alreadyJoinedRelNames = new HashSet<String>();


    // Get candidates from all relations to be joined
    List<RelationNode> candidates = getSmallerRelations(relationMap, remainRelNames);


    LogicalNode lastOne = candidates.get(0); // Get the first candidate relation (i.e., smallest)
    remainRelNames.remove(((RelationNode)lastOne).getCanonicalName()); // Remove the first candidate relation


    // Add the first candidate to the set of joined relations
    alreadyJoinedRelNames.add(((RelationNode)lastOne).getCanonicalName());


    List<CandidateJoinNode> orderedJoins;
    CandidateJoinNode chosen = null;
    while(true) {
      // Get a set of relations that can be joined to the composite relation.
      Set<CandidateJoin> joinCandidates = new HashSet<CandidateJoin>();
      for (String currentRel : alreadyJoinedRelNames) {
        // find all relations that can be joined to this relation
        Collection<JoinEdge> edges = joinGraph.getJoinsWith(currentRel);


        if (edges.size() > 0) { // if there are available join quals
          for (JoinEdge edge : edges) {
            if (alreadyJoinedRelNames.contains(edge.getLeftRelation())
                && currentRel.contains(edge.getRightRelation())) { // if two relations are already joined
              continue;
            }


            if (!alreadyJoinedRelNames.contains(edge.getLeftRelation())) {
              joinCandidates.add(new CandidateJoin(edge.getLeftRelation(), edge)) ;
            }
            if (!alreadyJoinedRelNames.contains(edge.getRightRelation())) {
              joinCandidates.add(new CandidateJoin(edge.getRightRelation(), edge));
            }
          }
        } else {
          for (RelationNode rel : block.getRelations()) {
            // Add all relations except for itself to join candidates
            if (!currentRel.equals(rel.getCanonicalName())) {
              joinCandidates.add(new CandidateJoin(rel.getCanonicalName(),
                  new JoinEdge(JoinType.CROSS, currentRel, rel.getCanonicalName())));
            }
          }
        }
      }

      qualifier = CatalogUtil.buildFQName(resolvedDatabaseName, columnRef.getQualifier());
      canonicalName = CatalogUtil.buildFQName(qualifier, columnRef.getName());
    }
    qualifiedName = CatalogUtil.buildFQName(qualifier, columnRef.getName());


    RelationNode relationOp = block.getRelation(qualifier);


    // if a column name is outside of this query block
    if (relationOp == null) {
      // TODO - nested query can only refer outer query block? or not?
      for (QueryBlock eachBlock : queryBlocks.values()) {
        if (eachBlock.existsRelation(qualifier)) {
          relationOp = eachBlock.getRelation(qualifier);
        }
      }
    }


    // If we cannot find any relation against a qualified column name
    if (relationOp == null) {
      throw new NoSuchColumnException(canonicalName);
    }


    if (block.isAlreadyRenamedTableName(CatalogUtil.extractQualifier(canonicalName))) {
      String changedName = CatalogUtil.buildFQName(
          relationOp.getCanonicalName(),
          CatalogUtil.extractSimpleName(canonicalName));
      canonicalName = changedName;
    }


    Schema schema = relationOp.getTableSchema();
    Column column = schema.getColumn(canonicalName);
    if (column == null) {
      throw new NoSuchColumnException(canonicalName);
    }

Examples of org.apache.tajo.engine.planner.logical.RelationNode

Related Classes of org.apache.tajo.engine.planner.logical.RelationNode