Examples with LateralViewJoinDesc org.apache.hadoop.hive.ql.plan.LateralViewJoinDesc used on opensource projects

Example 1 with LateralViewJoinDesc

use of org.apache.hadoop.hive.ql.plan.LateralViewJoinDesc in project hive by apache.

the class SemanticAnalyzer method genLateralViewPlan.

private Operator genLateralViewPlan(QB qb, Operator op, ASTNode lateralViewTree) throws SemanticException {
    RowResolver lvForwardRR = new RowResolver();
    RowResolver source = opParseCtx.get(op).getRowResolver();
    Map<String, ExprNodeDesc> lvfColExprMap = new HashMap<String, ExprNodeDesc>();
    Map<String, ExprNodeDesc> selColExprMap = new HashMap<String, ExprNodeDesc>();
    List<ExprNodeDesc> colList = new ArrayList<ExprNodeDesc>();
    List<String> colNames = new ArrayList<String>();
    for (ColumnInfo col : source.getColumnInfos()) {
        String[] tabCol = source.reverseLookup(col.getInternalName());
        lvForwardRR.put(tabCol[0], tabCol[1], col);
        ExprNodeDesc colExpr = new ExprNodeColumnDesc(col);
        colList.add(colExpr);
        colNames.add(colExpr.getName());
        lvfColExprMap.put(col.getInternalName(), colExpr);
        selColExprMap.put(col.getInternalName(), colExpr.clone());
    }
    Operator lvForward = putOpInsertMap(OperatorFactory.getAndMakeChild(new LateralViewForwardDesc(), new RowSchema(lvForwardRR.getColumnInfos()), op), lvForwardRR);
    lvForward.setColumnExprMap(lvfColExprMap);
    // The order in which the two paths are added is important. The
    // lateral view join operator depends on having the select operator
    // give it the row first.
    // Get the all path by making a select(*).
    RowResolver allPathRR = opParseCtx.get(lvForward).getRowResolver();
    // Operator allPath = op;
    SelectDesc sDesc = new SelectDesc(colList, colNames, false);
    sDesc.setSelStarNoCompute(true);
    Operator allPath = putOpInsertMap(OperatorFactory.getAndMakeChild(sDesc, new RowSchema(allPathRR.getColumnInfos()), lvForward), allPathRR);
    allPath.setColumnExprMap(selColExprMap);
    int allColumns = allPathRR.getColumnInfos().size();
    // Get the UDTF Path
    QB blankQb = new QB(null, null, false);
    Operator udtfPath = genSelectPlan(null, (ASTNode) lateralViewTree.getChild(0), blankQb, lvForward, null, lateralViewTree.getType() == HiveParser.TOK_LATERAL_VIEW_OUTER);
    // add udtf aliases to QB
    for (String udtfAlias : blankQb.getAliases()) {
        qb.addAlias(udtfAlias);
    }
    RowResolver udtfPathRR = opParseCtx.get(udtfPath).getRowResolver();
    // Merge the two into the lateral view join
    // The cols of the merged result will be the combination of both the
    // cols of the UDTF path and the cols of the all path. The internal
    // names have to be changed to avoid conflicts
    RowResolver lateralViewRR = new RowResolver();
    ArrayList<String> outputInternalColNames = new ArrayList<String>();
    // For PPD, we need a column to expression map so that during the walk,
    // the processor knows how to transform the internal col names.
    // Following steps are dependant on the fact that we called
    // LVmerge.. in the above order
    Map<String, ExprNodeDesc> colExprMap = new HashMap<String, ExprNodeDesc>();
    LVmergeRowResolvers(allPathRR, lateralViewRR, colExprMap, outputInternalColNames);
    LVmergeRowResolvers(udtfPathRR, lateralViewRR, colExprMap, outputInternalColNames);
    Operator lateralViewJoin = putOpInsertMap(OperatorFactory.getAndMakeChild(new LateralViewJoinDesc(allColumns, outputInternalColNames), new RowSchema(lateralViewRR.getColumnInfos()), allPath, udtfPath), lateralViewRR);
    lateralViewJoin.setColumnExprMap(colExprMap);
    return lateralViewJoin;
}