IIUC, default partition constraints is simply NOT IN (<values of all other sibling partitions>). If constraint on the default partition refutes the new partition's constraints that means we have overlapping partition, and perhaps error.
You are correct Amul, but this error will be thrown before we try to
check for the default partition data. So, in such cases I think we really
do not need to have logic to check if default partition refutes the new
