public void visit(Component component) {
final List<ValueExpression> hashExpressions = component.getHashExpressions();
if (hashExpressions != null) {
_afterProjection.addAll(hashExpressions);
_veList.addAll(hashExpressions);
}
final List<Operator> operators = component.getChainOperator().getOperators();
for (final Operator op : operators) op.accept(this);
}
public static Component getLCM(Component first, Component second) {
// TODO problem nested: we have multiple children
Component resultComp = first;
List<String> resultAnc = ParserUtil.getSourceNameList(resultComp);
while (!resultAnc.contains(second.getName())) {
resultComp = resultComp.getChild();
resultAnc = ParserUtil.getSourceNameList(resultComp);
}
return resultComp;
}
/*
* Is component a child (not necessarily first generation) of all orCompNames?
* Used in Cost-based optimizer
*/
public static boolean isLCM(Component component, Set<String> orCompNames) {
// dealing with parents
Component[] parents = component.getParents();
if (parents == null) {
// if I don't have parents I can't be LCM (I am DataSourceComponent)
return false;
}
for (int i = 0; i < parents.length; i++) {
Component parent = parents[i];
Set<String> parentAncestors = ParserUtil.getSourceNameSet(parent);
if (contains(parentAncestors, orCompNames)) {
// my parent is LCM (or its parent)
return false;
}
}
// if I contain all the mentioned sources, and none of my parent does so, than I am LCM
Set<String> compAncestors = ParserUtil.getSourceNameSet(component);
return contains(compAncestors, orCompNames);
}