Example #1
0
  @Override
  public int execute(DriverContext driverContext) {

    PrintStream out = null;
    try {
      Path resFile = new Path(work.getResFile());
      OutputStream outS = resFile.getFileSystem(conf).create(resFile);
      out = new PrintStream(outS);

      QB qb = work.getQb();
      TokenRewriteStream stream = work.getCtx().getTokenRewriteStream();
      String program = "sq rewrite";
      ASTNode ast = work.getAst();

      try {
        addRewrites(stream, qb, program, out);
        out.println(
            "\nRewritten Query:\n"
                + stream.toString(program, ast.getTokenStartIndex(), ast.getTokenStopIndex()));
      } finally {
        stream.deleteProgram(program);
      }

      out.close();
      out = null;
      return (0);
    } catch (Exception e) {
      console.printError(
          "Failed with exception " + e.getMessage(), "\n" + StringUtils.stringifyException(e));
      return (1);
    } finally {
      IOUtils.closeStream(out);
    }
  }
Example #2
0
  void addRewrites(
      TokenRewriteStream stream,
      QBSubQuery sq,
      String program,
      PrintStream out,
      String qbAlias,
      boolean isWhere,
      StringBuilder addedJoins) {
    ASTNode sqNode = sq.getOriginalSubQueryASTForRewrite();
    ASTNode tokQry = getQueryASTNode(sqNode);
    ASTNode tokInsert = (ASTNode) tokQry.getChild(1);
    ASTNode tokWhere = null;

    for (int i = 0; i < tokInsert.getChildCount(); i++) {
      if (tokInsert.getChild(i).getType() == HiveParser.TOK_WHERE) {
        tokWhere = (ASTNode) tokInsert.getChild(i);
        break;
      }
    }

    SubQueryDiagnostic.QBSubQueryRewrite diag = sq.getDiagnostic();
    String sqStr = diag.getRewrittenQuery();
    String joinCond = diag.getJoiningCondition();

    /*
     * the SubQuery predicate has been hoisted as a Join. The SubQuery predicate is replaced
     * by a 'true' predicate in the Outer QB's where/having clause.
     */
    stream.replace(program, sqNode.getTokenStartIndex(), sqNode.getTokenStopIndex(), "1 = 1");

    String sqJoin = " " + getJoinKeyWord(sq) + " " + sqStr + " " + joinCond;
    addedJoins.append(" ").append(sqJoin);

    String postJoinCond = diag.getOuterQueryPostJoinCond();
    if (postJoinCond != null) {
      stream.insertAfter(program, tokWhere.getTokenStopIndex(), " and " + postJoinCond);
    }

    String qualifier = isWhere ? "Where Clause " : "Having Clause ";
    if (qbAlias != null) {
      qualifier = qualifier + "for Query Block '" + qbAlias + "' ";
    }
    out.println(String.format("\n%s Rewritten SubQuery:\n%s", qualifier, diag.getRewrittenQuery()));
    out.println(
        String.format(
            "\n%s SubQuery Joining Condition:\n%s", qualifier, diag.getJoiningCondition()));
  }