I sort of want the opposite. Except for extremely high velocity mutable data, why do we ever drop an old version of any record? I want the whole database to look more like git commits - completely immutable, versionable, every change attributable to a specific commit, connection, client, user.
So much complexity and stress and work at the moment comes from the fear of data loss or corruption. Schema updates, migrations, backups, all the distributed computing stuff where every node has to assume every other node could have mutated the data .... And then there are countless applications full of "history" type tables to reinstate audit trails for the mutable data. It's kind of ridiculous when you think about it.
It all made sense when storage was super expensive but these days all the counter measures we have to implement to deal with mutable state are far more expensive than just using more disk space.
If the old versions of records stay where they are, they will start to dominate heap pages and lead to a kind of heap fragmentation. If the records are still indexed, then they will create an enormous index bloat. Both of these will make caches less effective and either require more RAM or IOPS, both of which are scarce in a relational db.
You probably need a drastically different strategy, like moving old records to separate cold storage instead (assuming you might ocassionally want to query it. Otherwise you can just retain your WAL files forever).
Absolutely ... it needs to be designed from the ground up - why I think it fits the question of something a modern database could do that Postgres would struggle with.
So much complexity and stress and work at the moment comes from the fear of data loss or corruption. Schema updates, migrations, backups, all the distributed computing stuff where every node has to assume every other node could have mutated the data .... And then there are countless applications full of "history" type tables to reinstate audit trails for the mutable data. It's kind of ridiculous when you think about it.
It all made sense when storage was super expensive but these days all the counter measures we have to implement to deal with mutable state are far more expensive than just using more disk space.