org.apache.hadoop.hive.ql.ppd
Class OpProcFactory

java.lang.Object
  org.apache.hadoop.hive.ql.ppd.OpProcFactory

public final 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.

Nested Class Summary

static class	OpProcFactory.DefaultPPD Default processor which just merges its children.
static class	OpProcFactory.FilterPPD Determines the push down predicates in its where expression and then combines it with the push down predicates that are passed from its children.
static class	OpProcFactory.JoinerPPD Determines predicates for which alias can be pushed to it's parents.
static class	OpProcFactory.JoinPPD
static class	OpProcFactory.LateralViewForwardPPD
static class	OpProcFactory.ScriptPPD Processor for Script Operator Prevents any predicates being pushed.
static class	OpProcFactory.TableScanPPD Combines predicates of its child into a single expression and adds a filter op as new child.
static class	OpProcFactory.UDTFPPD

Method Summary

static NodeProcessor	getDefaultProc()
static NodeProcessor	getFilterProc()
static NodeProcessor	getJoinProc()
static NodeProcessor	getLIMProc()
static NodeProcessor	getLVFProc()
static NodeProcessor	getLVJProc()
static NodeProcessor	getPTFProc()
static NodeProcessor	getSCRProc()
static NodeProcessor	getTSProc()
static NodeProcessor	getUDTFProc()

Methods inherited from class java.lang.Object

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

Method Detail

getFilterProc

public static NodeProcessor getFilterProc()

getJoinProc

public static NodeProcessor getJoinProc()

getTSProc

public static NodeProcessor getTSProc()

getDefaultProc

public static NodeProcessor getDefaultProc()

getPTFProc

public static NodeProcessor getPTFProc()

getSCRProc

public static NodeProcessor getSCRProc()

getLIMProc

public static NodeProcessor getLIMProc()

getLVFProc

public static NodeProcessor getLVFProc()

getUDTFProc

public static NodeProcessor getUDTFProc()

getLVJProc

public static NodeProcessor getLVJProc()