Examples of org.apache.hadoop.hive.ql.optimizer.physical.MetadataOnlyOptimizer$FileSinkProcessor

Package org.apache.hadoop.hive.ql.optimizer.physical

Examples of org.apache.hadoop.hive.ql.optimizer.physical.MetadataOnlyOptimizer$FileSinkProcessor

org.apache.hadoop.hive.ql.optimizer.physical.MetadataOnlyOptimizer
MetadataOnlyOptimizer determines to which TableScanOperators "metadata only" optimization can be applied. Such operator must use only partition columns (it is easy to check, because we are after column pruning and all places where the data from the operator is used must go through GroupByOperator distinct or distinct-like aggregations. Aggregation is distinct-like if adding distinct wouldn't change the result, for example min, max. We cannot apply the optimization without group by, because the results depend on the numbers of rows in partitions, for example count(hr) will count all rows in matching partitions.

    } else {
      LOG.debug("Skipping null scan query optimization");
    }


    if (conf.getBoolVar(HiveConf.ConfVars.HIVEMETADATAONLYQUERIES)) {
      physicalCtx = new MetadataOnlyOptimizer().resolve(physicalCtx);
    } else {
      LOG.debug("Skipping metadata only query optimization");
    }


    if (conf.getBoolVar(HiveConf.ConfVars.HIVE_CHECK_CROSS_PRODUCT)) {

View Full Code Here

TOP

Related Classes of org.apache.hadoop.hive.ql.optimizer.physical.MetadataOnlyOptimizer$FileSinkProcessor

org.apache.hadoop.fs.Path

org.apache.hadoop.hive.ql.exec.GroupByOperator

org.apache.hadoop.hive.ql.exec.TableScanOperator

org.apache.hadoop.hive.ql.lib.DefaultGraphWalker

org.apache.hadoop.hive.ql.lib.DefaultRuleDispatcher

org.apache.hadoop.hive.ql.lib.Dispatcher

org.apache.hadoop.hive.ql.lib.GraphWalker

org.apache.hadoop.hive.ql.lib.PreOrderWalker

org.apache.hadoop.hive.ql.lib.RuleRegExp

org.apache.hadoop.hive.ql.parse.ParseContext

All source code are property of their respective owners. Java is a trademark of Sun Microsystems, Inc and owned by ORACLE Inc. Contact coftware#gmail.com.