⟩ What is row chaining and row migration?
We will migrate a row when an update to that row would cause it to not fit on the block anymore (with all of the other data that exists there currently). A migration means that the entire row will move and we just leave behind the. So, the original block just has the rowid of the new block and the entire row is moved.
Row chaining nstead of just having a forwarding address on one block and the data on another we have data on two or more blocks.