org.apache.hadoop.hive.ql.ppd
Class OpProcFactory
java.lang.Object
org.apache.hadoop.hive.ql.ppd.OpProcFactory
public class OpProcFactory
- extends Object
Operator factory for predicate pushdown processing of operator graph
Each operator determines the pushdown predicates by walking the expression tree.
Each operator merges its own pushdown predicates with those of its children
Finally the TableScan operator gathers all the predicates and inserts a filter operator
after itself.
TODO: Further optimizations
1) Multi-insert case
2) Create a filter operator for those predicates that couldn't be pushed to the previous
operators in the data flow
3) Merge multiple sequential filter predicates into so that plans are more readable
4) Remove predicates from filter operators that have been pushed. Currently these pushed
predicates are evaluated twice.
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
OpProcFactory
public OpProcFactory()
createFilter
protected static Object createFilter(Operator op,
ExprWalkerInfo pushDownPreds,
OpWalkerInfo owi)
getFilterProc
public static NodeProcessor getFilterProc()
getJoinProc
public static NodeProcessor getJoinProc()
getRSProc
public static NodeProcessor getRSProc()
getTSProc
public static NodeProcessor getTSProc()
getDefaultProc
public static NodeProcessor getDefaultProc()
getSCRProc
public static NodeProcessor getSCRProc()
getLIMProc
public static NodeProcessor getLIMProc()
Copyright © 2009 The Apache Software Foundation