///////////////////////////////// HYPERGRAPH NODE
// /////////////////////////////////////////////////
private ISkolemPart generateHyperGraphSkolemFunction(
SkolemFunctionGenerator generator, MappingTask mappingTask) {
// initialize data structures
Map<SetAlias, List<GeneratorWithPath>> generatorsByAlias =
new HashMap<SetAlias, List<GeneratorWithPath>>();
Map<SetAlias, ISkolemPart> partsByAlias = new HashMap<SetAlias, ISkolemPart>();
Map<VariableJoinCondition, ISkolemPart> partsForJoins =
new HashMap<VariableJoinCondition, ISkolemPart>();
initializeDataStructures(
generator, generatorsByAlias, partsByAlias, partsForJoins, mappingTask);
// generate tuple strings
ISkolemPart partForTuples = generatePartForTuples(partsByAlias, mappingTask);
ISkolemPart partForJoins = generatePartForJoins(generator, partsForJoins, mappingTask);
ISkolemPart partForVariable = generatePartForVariable(generator, partsForJoins, mappingTask);
ISkolemPart result = new AppendSkolemPart();
result.addChild(new StringSkolemPart("SK("));
result.addChild(new StringSkolemPart("Tuples="));
result.addChild(partForTuples);
result.addChild(new StringSkolemPart("**Joins="));
result.addChild(partForJoins);
if (generator.getTgd().getTargetView().getAllJoinConditions().size() > 1) {
result.addChild(new StringSkolemPart("**Var="));
result.addChild(partForVariable);
}
if (generator.getPosition() != null) {
result.addChild(new StringSkolemPart("**Pos=" + generator.getPosition()));
}
result.addChild(new StringSkolemPart(")"));
return result;
}
///////////////////////////////// LOCAL NODE /////////////////////////////////////////////////
private ISkolemPart generateLocalSkolemFunction(
SkolemFunctionGenerator generator, MappingTask mappingTask) {
StringBuilder functionName = new StringBuilder();
functionName.append("SK_");
functionName.append("TGD").append(compactHashCode(generator.getTgd().hashCode())).append("_");
functionName
.append("N")
.append(compactHashCode(generator.getJoinConditions().toString().hashCode()));
if (generator.getPosition() != null) {
functionName.append("_Pos=").append(generator.getPosition());
}
return generateAppendWithFunctionName(functionName.toString(), generator, mappingTask);
}
///////////////////////////////// KEY NODE /////////////////////////////////////////////////
private ISkolemPart generateSkolemFunctionForKey(
SkolemFunctionGenerator generator, MappingTask mappingTask) {
StringBuilder functionName = new StringBuilder();
functionName.append("SK_");
//
// functionName.append("TGD_").append(compactHashCode(generator.getTgd().hashCode())).append("_");
functionName
.append("KEY_")
.append(compactHashCode(generator.getFunctionalDependencies().get(0).hashCode()));
if (generator.getPosition() != null) {
functionName.append("_Pos=").append(generator.getPosition());
}
return generateAppendWithFunctionName(functionName.toString(), generator, mappingTask);
}
