There are obviously ways you could accomplish it. RocksDB’s Merge operator uses this as one of the canonical examples - your update records just the new value t

There are obviously ways you could accomplish it. RocksDB’s Merge operator uses this as one of the canonical examples - your update records just the new value through a merge record. When you go to retrieve, you have to keep going through delta updates to reconstruct what the value is now & you only rewrite the value as part of a large compaction process. This way the cost of the write is the cost of the delta, the read cost is impacted although in practice negligible if you use a row cache, and the cost of rewriting the document is amortized into a much larger operation.