@Override
  public void analyzeInternal(ASTNode root) throws SemanticException {
    if (root.getChildCount() == 0 || root.getChildCount() > 2) {
      throw new SemanticException("Unexpected Tokens at DESCRIBE CONNECTOR");
    }

    ctx.setResFile(ctx.getLocalTmpPath());

    String connectorName = stripQuotes(root.getChild(0).getText());
    boolean isExtended = root.getChildCount() == 2;

    inputs.add(new ReadEntity(getDataConnector(connectorName)));

    DescDataConnectorDesc desc = new DescDataConnectorDesc(ctx.getResFile(), connectorName, isExtended);
    Task<DDLWork> task = TaskFactory.get(new DDLWork(getInputs(), getOutputs(), desc));
    rootTasks.add(task);

    task.setFetchSource(true);
    setFetchTask(createFetchTask(desc.getSchema()));
  }
Analyzer for data connector description commands.
ql/src/java/org/apache/hadoop/hive/ql/ddl/dataconnector/desc/DescDataConnectorAnalyzer.java