Examples with MapRedTask org.apache.hadoop.hive.ql.exec.mr.MapRedTask used on opensource projects

Example 21 with MapRedTask

use of org.apache.hadoop.hive.ql.exec.mr.MapRedTask in project hive by apache.

the class GenMRTableScan1 method process.

/**
 * Table Sink encountered.
 * @param nd
 *          the table sink operator encountered
 * @param opProcCtx
 *          context
 */
@Override
public Object process(Node nd, Stack<Node> stack, NodeProcessorCtx opProcCtx, Object... nodeOutputs) throws SemanticException {
    TableScanOperator op = (TableScanOperator) nd;
    GenMRProcContext ctx = (GenMRProcContext) opProcCtx;
    ctx.reset();
    ParseContext parseCtx = ctx.getParseCtx();
    Table table = op.getConf().getTableMetadata();
    Class<? extends InputFormat> inputFormat = table.getInputFormatClass();
    Map<Operator<? extends OperatorDesc>, GenMapRedCtx> mapCurrCtx = ctx.getMapCurrCtx();
    // create a dummy MapReduce task
    MapredWork currWork = GenMapRedUtils.getMapRedWork(parseCtx);
    MapRedTask currTask = (MapRedTask) TaskFactory.get(currWork);
    ctx.setCurrTask(currTask);
    ctx.setCurrTopOp(op);
    for (String alias : parseCtx.getTopOps().keySet()) {
        Operator<? extends OperatorDesc> currOp = parseCtx.getTopOps().get(alias);
        if (currOp == op) {
            String currAliasId = alias;
            ctx.setCurrAliasId(currAliasId);
            mapCurrCtx.put(op, new GenMapRedCtx(currTask, currAliasId));
            if (parseCtx.getQueryProperties().isAnalyzeCommand()) {
                boolean noScan = parseCtx.getQueryProperties().isNoScanAnalyzeCommand();
                if (BasicStatsNoJobTask.canUseBasicStats(table, inputFormat)) {
                    // For ORC and Parquet, all the following statements are the same
                    // ANALYZE TABLE T [PARTITION (...)] COMPUTE STATISTICS
                    // ANALYZE TABLE T [PARTITION (...)] COMPUTE STATISTICS noscan;
                    // There will not be any MR or Tez job above this task
                    StatsWork statWork = new StatsWork(table, parseCtx.getConf());
                    statWork.setFooterScan();
                    // If partition is specified, get pruned partition list
                    Set<Partition> confirmedParts = GenMapRedUtils.getConfirmedPartitionsForScan(op);
                    if (confirmedParts.size() > 0) {
                        List<String> partCols = GenMapRedUtils.getPartitionColumns(op);
                        PrunedPartitionList partList = new PrunedPartitionList(table, confirmedParts, partCols, false);
                        statWork.addInputPartitions(partList.getPartitions());
                    }
                    Task<StatsWork> snjTask = TaskFactory.get(statWork);
                    ctx.setCurrTask(snjTask);
                    ctx.setCurrTopOp(null);
                    ctx.getRootTasks().clear();
                    ctx.getRootTasks().add(snjTask);
                } else {
                    // ANALYZE TABLE T [PARTITION (...)] COMPUTE STATISTICS;
                    // The plan consists of a simple MapRedTask followed by a StatsTask.
                    // The MR task is just a simple TableScanOperator
                    BasicStatsWork statsWork = new BasicStatsWork(table.getTableSpec());
                    statsWork.setIsExplicitAnalyze(true);
                    statsWork.setNoScanAnalyzeCommand(noScan);
                    StatsWork columnStatsWork = new StatsWork(table, statsWork, parseCtx.getConf());
                    columnStatsWork.collectStatsFromAggregator(op.getConf());
                    columnStatsWork.setSourceTask(currTask);
                    Task<StatsWork> columnStatsTask = TaskFactory.get(columnStatsWork);
                    currTask.addDependentTask(columnStatsTask);
                    if (!ctx.getRootTasks().contains(currTask)) {
                        ctx.getRootTasks().add(currTask);
                    }
                    // The plan consists of a StatsTask only.
                    if (noScan) {
                        columnStatsTask.setParentTasks(null);
                        ctx.getRootTasks().remove(currTask);
                        ctx.getRootTasks().add(columnStatsTask);
                    }
                    currWork.getMapWork().setGatheringStats(true);
                    if (currWork.getReduceWork() != null) {
                        currWork.getReduceWork().setGatheringStats(true);
                    }
                    // NOTE: here we should use the new partition predicate pushdown API to get a list of
                    // pruned list,
                    // and pass it to setTaskPlan as the last parameter
                    Set<Partition> confirmedPartns = GenMapRedUtils.getConfirmedPartitionsForScan(op);
                    if (confirmedPartns.size() > 0) {
                        List<String> partCols = GenMapRedUtils.getPartitionColumns(op);
                        PrunedPartitionList partList = new PrunedPartitionList(table, confirmedPartns, partCols, false);
                        GenMapRedUtils.setTaskPlan(currAliasId, op, currTask, false, ctx, partList);
                    } else {
                        // non-partitioned table
                        GenMapRedUtils.setTaskPlan(currAliasId, op, currTask, false, ctx);
                    }
                }
            }
            return true;
        }
    }
    assert false;
    return null;
}