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

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

public class ConstantInPatternOptimiser
extends Optimiser

Detects equality filters between a var and a constant, deletes the filter and replaces the var in generators with the constant

Author:

Lucas Zamboulis

Field Summary

Fields inherited from class uk.ac.bbk.dcs.automed.qproc.optimise.Optimiser

logger, targets

Constructor Summary

ConstantInPatternOptimiser(QueryOptimisationProvider qop)

Method Summary

protected Cell	generateNewEquiFun(Cell op, Cell con, Cell op1, Cell op2)
protected Cell	generateNewEquiFunHelp(Cell op, Cell con, Cell opEqualOp, Cell otherOp)
static void	main(java.lang.String[] args)
protected boolean	noVar(Cell c)
boolean	optimise(Cell c, QueryProcessorConfiguration qpc)
protected int	replaceVar(Cell pat, java.util.Map m) Go through pattern and replace var/tuple with constant if needed

Methods inherited from class uk.ac.bbk.dcs.automed.qproc.optimise.Optimiser

getValueBasedOptimisation, optimise, optimise, setValueBasedOptimisation

Methods inherited from class java.lang.Object

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

Constructor Detail

ConstantInPatternOptimiser

public ConstantInPatternOptimiser(QueryOptimisationProvider qop)

Method Detail

optimise

public boolean optimise(Cell c,
                        QueryProcessorConfiguration qpc)
                 throws QueryOptimisationException

Specified by:

optimise in class Optimiser

Throws:

QueryOptimisationException

generateNewEquiFun

protected Cell generateNewEquiFun(Cell op,
                                  Cell con,
                                  Cell op1,
                                  Cell op2)

generateNewEquiFunHelp

protected Cell generateNewEquiFunHelp(Cell op,
                                      Cell con,
                                      Cell opEqualOp,
                                      Cell otherOp)

replaceVar

protected int replaceVar(Cell pat,
                         java.util.Map m)

Go through pattern and replace var/tuple with constant if needed

Parameters:

pat - input pattern

m - contains mappings between variables/tuples and constants

noVar

protected boolean noVar(Cell c)

main

public static void main(java.lang.String[] args)