org.apache.hadoop.hive.ql.optimizer.pcr
Class PcrExprProcFactory

java.lang.Object
  org.apache.hadoop.hive.ql.optimizer.pcr.PcrExprProcFactory

public final class PcrExprProcFactory
extends Object

Expression processor factory for partition condition removing. Each processor tries to calculate a result vector from its children's result vectors. Each element is the result for one of the pruned partitions. It also generates node by Modifying expr trees with partition conditions removed

Nested Class Summary

static class	PcrExprProcFactory.ColumnExprProcessor Processor for column expressions.
static class	PcrExprProcFactory.DefaultExprProcessor Processor for constants and null expressions.
static class	PcrExprProcFactory.FieldExprProcessor FieldExprProcessor.
static class	PcrExprProcFactory.GenericFuncExprProcessor Processor for Generic functions If it is AND, OR or NOT, we replace the node to be the constant true or false if we are sure the result from children, or cut one of the child if we know partial results.
static class	PcrExprProcFactory.NodeInfoWrapper
static class	PcrExprProcFactory.WalkState

Method Summary

static NodeProcessor	getColumnProcessor()
static NodeProcessor	getDefaultExprProcessor()
static NodeProcessor	getFieldProcessor()
static NodeProcessor	getGenericFuncProcessor()
static ExprNodeGenericFuncDesc	getOutExpr(ExprNodeGenericFuncDesc funcExpr, Object[] nodeOutputs)
static PcrExprProcFactory.NodeInfoWrapper	walkExprTree(String tabAlias, ArrayList<Partition> parts, List<VirtualColumn> vcs, ExprNodeDesc pred) Remove partition conditions when necessary from the the expression tree.

Methods inherited from class java.lang.Object

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

Method Detail

getOutExpr

public static ExprNodeGenericFuncDesc getOutExpr(ExprNodeGenericFuncDesc funcExpr,
                                                 Object[] nodeOutputs)

getDefaultExprProcessor

public static NodeProcessor getDefaultExprProcessor()

getGenericFuncProcessor

public static NodeProcessor getGenericFuncProcessor()

getFieldProcessor

public static NodeProcessor getFieldProcessor()

getColumnProcessor

public static NodeProcessor getColumnProcessor()

walkExprTree

public static PcrExprProcFactory.NodeInfoWrapper walkExprTree(String tabAlias,
                                                              ArrayList<Partition> parts,
                                                              List<VirtualColumn> vcs,
                                                              ExprNodeDesc pred)
                                                       throws SemanticException

Remove partition conditions when necessary from the the expression tree.

Parameters:

tabAlias - the table alias

parts - the list of all pruned partitions for the table

vcs - virtual columns referenced

pred - expression tree of the target filter operator

Returns:

the node information of the root expression

Throws:

SemanticException