org.apache.hadoop.hive.ql.optimizer.topnkey

Class CommonKeyPrefix

java.lang.Object

org.apache.hadoop.hive.ql.optimizer.topnkey.CommonKeyPrefix

public final class CommonKeyPrefix
extends Object

Holds result of a common key prefix of two operators. Provides factory methods for mapping TopNKey operator keys to GroupBy and ReduceSink operator keys.

Method Summary

Modifier and Type	Method and Description
void	add(ExprNodeDesc column, char order, char nullOrder)
List<ExprNodeDesc>	getMappedColumns()
String	getMappedNullOrder()
String	getMappedOrder()
boolean	isEmpty()
static CommonKeyPrefix	map(List<ExprNodeDesc> opKeys, String opOrder, String opNullOrder, List<ExprNodeDesc> parentKeys, Map<String,ExprNodeDesc> parentColExprMap, String parentOrder, String parentNullOrder) General factory method to map two operator keys.
static CommonKeyPrefix	map(List<ExprNodeDesc> opKeys, String opOrder, String opNullOrder, List<ExprNodeDesc> parentKeys, String parentOrder, String parentNullOrder)
static CommonKeyPrefix	map(TopNKeyDesc topNKeyDesc, GroupByDesc groupByDesc) Factory method to map a TopNKeyOperator's and a GroupByOperator's keys.
static CommonKeyPrefix	map(TopNKeyDesc topNKeyDesc, ReduceSinkDesc reduceSinkDesc) Factory method to map a TopNKeyOperator's and a ReduceSinkOperator's keys.
int	size()

Methods inherited from class java.lang.Object

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

Method Detail

map

public static CommonKeyPrefix map(TopNKeyDesc topNKeyDesc,
                                  GroupByDesc groupByDesc)

Factory method to map a TopNKeyOperator's and a GroupByOperator's keys. This method calls the map(List, String, String, List, Map, String, String) method to do the mapping. Since the GroupByDesc does not contains any ordering information TopNKeyDesc ordering is passed for both operators.

Parameters:

topNKeyDesc - TopNKeyDesc contains TopNKeyOperator keys.

groupByDesc - GroupByDesc contains GroupByOperator keys.

Returns:

CommonKeyPrefix object containing common key prefix of the mapped operators.

map

public static CommonKeyPrefix map(TopNKeyDesc topNKeyDesc,
                                  ReduceSinkDesc reduceSinkDesc)

Factory method to map a TopNKeyOperator's and a ReduceSinkOperator's keys. This method calls the map(List, String, String, List, Map, String, String) method to do the mapping.

Parameters:

topNKeyDesc - TopNKeyDesc contains TopNKeyOperator keys.

reduceSinkDesc - ReduceSinkDesc contains ReduceSinkOperator keys.

Returns:

CommonKeyPrefix object containing common key prefix of the mapped operators.

map

public static CommonKeyPrefix map(List<ExprNodeDesc> opKeys,
                                  String opOrder,
                                  String opNullOrder,
                                  List<ExprNodeDesc> parentKeys,
                                  Map<String,ExprNodeDesc> parentColExprMap,
                                  String parentOrder,
                                  String parentNullOrder)

General factory method to map two operator keys. Two keys are considered to be equal - if parent operator's parentColExprMap has an entry with the operator key column name - and that entry value has the same index as the operator key column index. - and both key columns has the same ordering - and both key columns has the same null ordering Ex.: op1: a, b, c, d op2: a, b, e result: a, b opKeys: Column[_col0], Column[_col1], Column[_col2], Column[_col3] parentKeys: Column[KEY._col0], Column[KEY._col1], Column[KEY._col4] parentColExprMap: {_col0 -> Column[KEY._col0]}, {_col1 -> Column[KEY._col1]}, {_col4 -> Column[KEY._col4]} Column ordering and null ordering is given by a string where each character represents a column order/null order. Ex.: a ASC NULLS FIRST, b DESC NULLS LAST, c ASC NULLS LAST -> order="+-+", null order="azz" When parentColExprMap is null this method falls back to map(List, String, String, List, String, String).

Parameters:

opKeys - List of ExprNodeDesc. contains the operator's key columns

opOrder - operator's key column ordering in String format

opNullOrder - operator's key column null ordering in String format

parentKeys - List of ExprNodeDesc. contains the parent operator's key columns

parentColExprMap - Map of String -> ExprNodeDesc. contains parent operator's key column name ExprNodeDesc mapping

parentOrder - parent operator's key column ordering in String format

parentNullOrder - parent operator's key column null ordering in String format

Returns:

CommonKeyPrefix object containing the common key prefix of the mapped operators.

map

public static CommonKeyPrefix map(List<ExprNodeDesc> opKeys,
                                  String opOrder,
                                  String opNullOrder,
                                  List<ExprNodeDesc> parentKeys,
                                  String parentOrder,
                                  String parentNullOrder)

add

public void add(ExprNodeDesc column,
                char order,
                char nullOrder)

isEmpty

public boolean isEmpty()

getMappedColumns

public List<ExprNodeDesc> getMappedColumns()

getMappedOrder

public String getMappedOrder()

getMappedNullOrder

public String getMappedNullOrder()

size

public int size()