[lichtenberger]

You can reconstruct a revision in O(n), you can search for a specific revision in O(log n) and the transaction time is stored in a revision root page (time the transaction commits). Thus, you do not have to store the time for each node (even start- and end-time).

Furthermore Sirix does not have to copy whole record pages which have changed, it depends on the chosen versioning algorithm. The whole structure is highly concurrent and allows client side parallelism. We also do not have to write in a WAL first, but the structure is always consistent (if no hardware failure occurs...).