uk.ac.bbk.dcs.automed.qproc.optimise.optimisers
Class CollectionOperatorReorganiser

java.lang.Object
  uk.ac.bbk.dcs.automed.qproc.optimise.optimisers.CollectionOperatorReorganiser

public class CollectionOperatorReorganiser
extends java.lang.Object

This optimiser is to reorganise the order of arguments in expressions containing ++, --, intersect & union operators, so that constructs from the same schema come closer in the query tree and therefore bigger sub queries can be sent to the a datasource wrapper. Note: the arguments to these collection operators are assumed to be either (a) schemes, or (b) of the form [h|p<-<>], h & p are patterns

Author:

Hao Fan, Lucas Zamboulis

Field Summary

protected java.util.logging.Logger

logger

Constructor Summary

CollectionOperatorReorganiser()
Considering the fellowing cases: $x ++ ($y ++ $z) // Two++A ($x ++ $y) ++ $z // Two++B ($x ++ $y) ++ ($z ++ $m) // Three++ $x -- ($y -- $z) // unchangable ($x -- $y) -- $z // Two-- ($x -- $y) -- ($z -- $m) // Three-- $x ++ ($y -- $z) // unchangable ($x -- $y) ++ $z // unchangable ($x -- $y) ++ ($z -- $m) // unchangable $x -- ($y ++ $z) // One--One++ ($x ++ $y) -- $z // unchangable ($x ++ $y) -- ($z ++ $m) // One++One--One++ ($x ++ $y) ++ ($z -- $m) // Two++One-- ($x -- $y) ++ ($z ++ $m) // One--Two++ ($x ++ $y) -- ($z -- $m) // unchangable ($x -- $y) -- ($z ++ $m) // Two--One++ $x union ($y union $z) // TwoUnionA ($x union $y) union $z // TwoUnionB ($x union $y) union ($z union $m) //ThreeUnion $x intersect ($y intersect $z) //TwoIntersectA ($x intersect $y) intersect $z //TwoIntersectB ($x intersect $y) intersect ($z intersect $m) //ThreeIntersect

Method Summary

boolean	apply(Cell c)
void	finalize()
boolean	optimise(ASG g)
boolean	optimise(Cell c)

Methods inherited from class java.lang.Object

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

Field Detail

logger

protected java.util.logging.Logger logger

Constructor Detail

CollectionOperatorReorganiser

public CollectionOperatorReorganiser()

Considering the fellowing cases: $x ++ ($y ++ $z) // Two++A ($x ++ $y) ++ $z // Two++B ($x ++ $y) ++ ($z ++ $m) // Three++ $x -- ($y -- $z) // unchangable ($x -- $y) -- $z // Two-- ($x -- $y) -- ($z -- $m) // Three-- $x ++ ($y -- $z) // unchangable ($x -- $y) ++ $z // unchangable ($x -- $y) ++ ($z -- $m) // unchangable $x -- ($y ++ $z) // One--One++ ($x ++ $y) -- $z // unchangable ($x ++ $y) -- ($z ++ $m) // One++One--One++ ($x ++ $y) ++ ($z -- $m) // Two++One-- ($x -- $y) ++ ($z ++ $m) // One--Two++ ($x ++ $y) -- ($z -- $m) // unchangable ($x -- $y) -- ($z ++ $m) // Two--One++ $x union ($y union $z) // TwoUnionA ($x union $y) union $z // TwoUnionB ($x union $y) union ($z union $m) //ThreeUnion $x intersect ($y intersect $z) //TwoIntersectA ($x intersect $y) intersect $z //TwoIntersectB ($x intersect $y) intersect ($z intersect $m) //ThreeIntersect

Method Detail

finalize

public void finalize()

Overrides:

finalize in class java.lang.Object

apply

public boolean apply(Cell c)
              throws java.lang.Exception

Throws:

java.lang.Exception

optimise

public boolean optimise(Cell c)
                 throws QueryOptimisationException

Throws:

QueryOptimisationException

optimise

public boolean optimise(ASG g)