def getSafeQueryPlan(self, init=True):
# we are interested in whether the separator represents
# a generic inequality constraint - if so, it doesn't matter which
# component it occurs in, as it must have the same
# constraint everywhere
representativeSeparator = self.separator[0]
if representativeSeparator.isInequality() and representativeSeparator.getInequalityConstraint().isGeneric():
self.replacementVal = "generic_%s" % representativeSeparator.getInequalityConstraint().getConstant()
else:
self.replacementVal = algorithm.attCounter()
# for webkb
if representativeSeparator.domainSize:
self.effectiveDomainSize = representativeSeparator.domainSize
d = self.disjunctiveQuery
self.usedSeparatorVars = d.getUsedSeparators()
d.applySeparator(self.separator, self.replacementVal)
if isinstance(d, query_exp.DisjunctiveQuery):
cons = []
for c in d.getComponents():
cons.append(query_exp.ConjunctiveQuery(query_exp.decomposeComponent(c)))
self.childDNF = query_exp.DNF(cons)
else:
self.childDNF = d
if init:
self.child = algorithm.getSafeOpenQueryPlanNaive(self.childDNF)
symbolString = str(algorithm.dom) + "_" + str(representativeSeparator)
self.lam = symbols(symbolString)* self.child.lam
else:
self.child = None
def getSafeQueryPlan(dnf):
if isinstance(dnf, query_exp.DNF):
cnf = dnf.toCNF().minimize()
else:
cnf = dnf.minimize()
symbolComponentsDNF = query_exp.computeSymbolComponentsDNF(dnf)
if len(symbolComponentsDNF) > 1:
termList = [query_exp.DNF((list(s))) for s in symbolComponentsDNF]
return ind_union.IndependentUnion(cnf, termList)
symbolComponents = query_exp.computeSymbolComponentsCNF(cnf)
# independent join
if len(symbolComponents) > 1:
termList = [query_exp.CNF(list(s)) for s in symbolComponents]
return ind_join.IndependentJoin(cnf, termList)
# inclusion/exclusion
if len(cnf.getDisjuncts()) > 1:
termList = []
coeffList = []
for x in powerset(cnf.getDisjuncts()):
if len(x):
termList.append(
query_exp.CNF(
[query_exp.DisjunctiveQuery(
[c.copy() for d in x for c in d.getComponents()]
)
]
)
)
coeffList.append((-1) ** len(x))
lexpr = nltk.Expression.fromstring
for i in range(len(termList)):
if coeffList[i] == 0:
continue
for j in range(i + 1, len(termList)):
if coeffList[j] == 0:
continue
p9termI = lexpr(termList[i].toProver9())
p9termJ = lexpr(termList[j].toProver9())
proverItoJ = nltk.Prover9Command(
p9termJ, assumptions=[p9termI])
proverJtoI = nltk.Prover9Command(
p9termI, assumptions=[p9termJ])
if proverItoJ.prove() and proverJtoI.prove():
coeffList[i] += coeffList[j]
coeffList[j] = 0
subplans = []
finalCoeffList = []
for ind, term in enumerate(termList):
if coeffList[ind] == 0:
continue
subplans.append(term)
finalCoeffList.append(coeffList[ind])
return incl_excl.InclusionExclusion(cnf, subplans, finalCoeffList)
d = cnf.getDisjuncts()[0]
symbolComponents = query_exp.computeSymbolComponentsDisjunct(d)
# independent union
if len(symbolComponents) > 1:
termList = [
query_exp.CNF(
[query_exp.DisjunctiveQuery(list(s))]
) for s in symbolComponents]
return ind_union.IndependentUnion(cnf, termList)
# ground tuple
if not d.hasVariables():
comInd = 0 # only one component in a ground tuple
rel = d.getComponents()[comInd].getRelations()[comInd]
return ground_tup.GroundTuple(cnf, d, rel)
# separator variable
separator = d.getSeparator()
if separator:
return ind_proj.IndependentProject(cnf, d, separator)
lexpr = nltk.Expression.fromstring
p9d = lexpr(d.toProver9())
for x in powerset(d.getRelations()):
if len(x) > 1:
proposedComponent = query_exp.Component(x)
# TODO(ericgribkoff) Fix query R(x,y),R(y,z),~R(z,x)
# right now prover9 is timing out on:
# p9 assertion: (R(x,y), ~R(z,x)) p9 kb: exists y x z.(R(x,y) &
# R(y,z) & -R(z,x))
# TODO(ericgribkoff) Temporary fix for the above problem
if any([r.isNegated() for r in x]):
continue
p9component = lexpr(proposedComponent.toProver9())
prover = nltk.Prover9Command(p9d, assumptions=[p9component])
componentFalse = nltk.Prover9Command(
lexpr(r'False'), assumptions=[p9component])
if (prover.prove() and not componentFalse.prove() and not any(
[proposedComponent.containedIn(c) for c in d.getComponents()]
)):
newConjQueries = []
newConjQueries.append(query_exp.ConjunctiveQuery(
query_exp.decomposeComponent(proposedComponent)))
for c in d.getComponents():
newConjQueries.append(query_exp.ConjunctiveQuery([c]))
newDNF = query_exp.DNF(newConjQueries)
return getSafeQueryPlan(newDNF)
raise UnsafeException("FAIL")