예제 #1
0
  @Override
  public void analyze(Analyzer analyzer) throws AnalysisException, AuthorizationException {
    super.analyze(analyzer);
    Table t = getTargetTable();
    String tableName = getDb() + "." + getTbl();

    // Verify there are no conflicts with partition columns.
    for (FieldSchema fs : t.getMetaStoreTable().getPartitionKeys()) {
      if (fs.getName().toLowerCase().equals(colName.toLowerCase())) {
        throw new AnalysisException("Cannot modify partition column: " + colName);
      }
      if (fs.getName().toLowerCase().equals(newColDef.getColName().toLowerCase())) {
        throw new AnalysisException(
            "Column name conflicts with existing partition column: " + newColDef.getColName());
      }
    }

    // Verify the column being modified exists in the table
    if (t.getColumn(colName) == null) {
      throw new AnalysisException(
          String.format("Column '%s' does not exist in table: %s", colName, tableName));
    }

    // Check that the new column def's name is valid.
    newColDef.analyze();
    // Verify that if the column name is being changed, the new name doesn't conflict
    // with an existing column.
    if (!colName.toLowerCase().equals(newColDef.getColName().toLowerCase())
        && t.getColumn(newColDef.getColName()) != null) {
      throw new AnalysisException("Column already exists: " + newColDef.getColName());
    }
  }
예제 #2
0
  /*
   * Builds a TDescribeTableResult that contains the result of a DESCRIBE FORMATTED
   * <table> command. For the formatted describe output the goal is to be exactly the
   * same as what Hive (via HiveServer2) outputs, for compatibility reasons. To do this,
   * Hive's MetadataFormatUtils class is used to build the results.
   */
  private static TDescribeTableResult describeTableFormatted(Table table) {
    TDescribeTableResult descResult = new TDescribeTableResult();
    descResult.results = Lists.newArrayList();

    org.apache.hadoop.hive.metastore.api.Table msTable = table.getMetaStoreTable().deepCopy();
    // Fixup the metastore table so the output of DESCRIBE FORMATTED matches Hive's.
    // This is to distinguish between empty comments and no comments (value is null).
    for (FieldSchema fs : msTable.getSd().getCols())
      fs.setComment(table.getColumn(fs.getName()).getComment());
    for (FieldSchema fs : msTable.getPartitionKeys()) {
      fs.setComment(table.getColumn(fs.getName()).getComment());
    }

    // To avoid initializing any of the SerDe classes in the metastore table Thrift
    // struct, create the ql.metadata.Table object by calling the empty c'tor and
    // then calling setTTable().
    org.apache.hadoop.hive.ql.metadata.Table hiveTable =
        new org.apache.hadoop.hive.ql.metadata.Table();
    hiveTable.setTTable(msTable);
    StringBuilder sb = new StringBuilder();
    // First add all the columns (includes partition columns).
    sb.append(
        MetaDataFormatUtils.getAllColumnsInformation(
            msTable.getSd().getCols(), msTable.getPartitionKeys()));
    // Add the extended table metadata information.
    sb.append(MetaDataFormatUtils.getTableInformation(hiveTable));

    for (String line : sb.toString().split("\n")) {
      // To match Hive's HiveServer2 output, split each line into multiple column
      // values based on the field delimiter.
      String[] columns = line.split(MetaDataFormatUtils.FIELD_DELIM);
      TResultRow resultRow = new TResultRow();
      for (int i = 0; i < NUM_DESC_FORMATTED_RESULT_COLS; ++i) {
        TColumnValue colVal = new TColumnValue();
        colVal.setString_val(null);
        if (columns.length > i) {
          // Add the column value.
          colVal.setString_val(columns[i]);
        }
        resultRow.addToColVals(colVal);
      }
      descResult.results.add(resultRow);
    }
    return descResult;
  }