public void pushDown(Node parent, Node child, Node newParent, String link, String newLink) {
Node temp = child;
if (link.toUpperCase().equals("LEFT")) {
parent.setLeft(child.getRight());
} else parent.setRight(child.getRight());
if (newLink.toUpperCase().equals("LEFT")) {
child.setRight(newParent.getLeft());
newParent.setLeft(child);
} else {
child.setRight(newParent.getRight());
newParent.setRight(child);
}
}
public void visit(Node parent, Node child, String link) {
Node nParent = parent;
Node nChild = child;
Node newParent = null;
Expression condition = null;
ArrayList<Object> operation = null;
if (nChild == null) return;
if (nChild.getOptName().equals("SELECT")) {
operation = (ArrayList<Object>) nChild.getValue();
condition = (Expression) operation.get(0);
newParent = nChild.getRight();
if (newParent.getLeft() != null && checkSchema(nChild.getSchema(), newParent.getSchema())) {
pushDown(parent, child, child.getRight(), link, "LEFT");
}
if (newParent.getRight() != null && checkSchema(nChild.getSchema(), newParent.getSchema())) {
pushDown(parent, child, child.getRight(), link, "RIGHT");
}
}
}