Consider the following commands, ran against trunk@0f054fee5c:
As you can see, this incorrectly brings back cell v2=3.
There is one definitive problem and a potential one:
- Merging rows must be commutative. If a shadowable tombstone is applied after a row tombstone, it will replace that tombstone; if a row marker shadows the shadowable tombstone before the row containing the original data is applied, then any dead cells in said data will be resurrected;
- Shadowable tombstones shouldn't compact away previous row tombstones or even deleted cells; if the relevant tombstones have been GCed from the base table, then a base table update won't carry them anymore (alongside a newer row marker).