org.apache.hadoop.hive.ql.optimizer.stats.annotation
Class StatsRulesProcFactory.TableScanStatsRule

java.lang.Object
  org.apache.hadoop.hive.ql.optimizer.stats.annotation.StatsRulesProcFactory.DefaultStatsRule
      org.apache.hadoop.hive.ql.optimizer.stats.annotation.StatsRulesProcFactory.TableScanStatsRule

All Implemented Interfaces:

NodeProcessor

Enclosing class:

StatsRulesProcFactory

public static class StatsRulesProcFactory.TableScanStatsRule
extends StatsRulesProcFactory.DefaultStatsRule
implements NodeProcessor

Collect basic statistics like number of rows, data size and column level statistics from the table. Also sets the state of the available statistics. Basic and column statistics can have one of the following states COMPLETE, PARTIAL, NONE. In case of partitioned table, the basic and column stats are aggregated together to table level statistics. Column statistics will not be collected if hive.stats.fetch.column.stats is set to false. If basic statistics is not available then number of rows will be estimated from file size and average row size (computed from schema).

Constructor Summary

StatsRulesProcFactory.TableScanStatsRule()

Method Summary

Object

process(Node nd, Stack<Node> stack, NodeProcessorCtx procCtx, Object... nodeOutputs) Generic process for all ops that don't have specific implementations.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

StatsRulesProcFactory.TableScanStatsRule

public StatsRulesProcFactory.TableScanStatsRule()

Method Detail

process

public Object process(Node nd,
                      Stack<Node> stack,
                      NodeProcessorCtx procCtx,
                      Object... nodeOutputs)
               throws SemanticException

Description copied from interface: NodeProcessor

Generic process for all ops that don't have specific implementations.

Specified by:

process in interface NodeProcessor

Overrides:

process in class StatsRulesProcFactory.DefaultStatsRule

Parameters:

nd - operator to process

procCtx - operator processor context

nodeOutputs - A variable argument list of outputs from other nodes in the walk

Returns:

Object to be returned by the process call

Throws:

SemanticException