LogicNode outerJoinSimplication(LogicNode root)
{
Expr extraFilter = null;
if (root is LogicFilter rf)
{
extraFilter = rf.filter_;
}
LogicNode ret = root;
root.VisitEach((parent, index, node) => {
if (node is LogicJoin)
{
if (parent != null)
{
parent.children_[index] = trySimplifyOuterJoin(node as LogicJoin, extraFilter);
}
else
{
ret = trySimplifyOuterJoin(node as LogicJoin, extraFilter);
}
}
});
return(ret);
}
