|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |
java.lang.Objectorg.apache.hadoop.hive.ql.optimizer.MapJoinProcessor
public class MapJoinProcessor
Implementation of one of the rule-based map join optimization. User passes hints to specify map-joins and during this optimization, all user specified map joins are converted to MapJoins - the reduce sink operator above the join are converted to map sink operators. In future, once statistics are implemented, this transformation can also be done based on costs.
Nested Class Summary | |
---|---|
static class |
MapJoinProcessor.CurrentMapJoin
CurrentMapJoin. |
static class |
MapJoinProcessor.Default
Default. |
static class |
MapJoinProcessor.MapJoinDefault
MapJoinDefault. |
static class |
MapJoinProcessor.MapJoinFS
MapJoinFS. |
static class |
MapJoinProcessor.MapJoinWalkerCtx
MapJoinWalkerCtx. |
Constructor Summary | |
---|---|
MapJoinProcessor()
empty constructor. |
Method Summary | |
---|---|
static void |
checkMapJoin(int mapJoinPos,
JoinCondDesc[] condns)
|
static NodeProcessor |
getCurrentMapJoin()
|
static NodeProcessor |
getDefault()
|
static NodeProcessor |
getMapJoinDefault()
|
static NodeProcessor |
getMapJoinFS()
|
ParseContext |
transform(ParseContext pactx)
Transform the query tree. |
Methods inherited from class java.lang.Object |
---|
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Constructor Detail |
---|
public MapJoinProcessor()
Method Detail |
---|
public static void checkMapJoin(int mapJoinPos, JoinCondDesc[] condns) throws SemanticException
SemanticException
public ParseContext transform(ParseContext pactx) throws SemanticException
transform
in interface Transform
pactx
- current parse context
SemanticException
public static NodeProcessor getMapJoinFS()
public static NodeProcessor getMapJoinDefault()
public static NodeProcessor getDefault()
public static NodeProcessor getCurrentMapJoin()
|
||||||||||
PREV CLASS NEXT CLASS | FRAMES NO FRAMES | |||||||||
SUMMARY: NESTED | FIELD | CONSTR | METHOD | DETAIL: FIELD | CONSTR | METHOD |