I wonder if anyone has made a collection of reference examples implemented this way (and in general think that a substantial compendium good examples of DB schema and thinking behind them could be worthwhile).
I realize you're not claiming those columns are useful from an application perspective. Just curious to know if I'm wrong and they are useful.
Because as I understand it, the selling point of Datomic is their audit trail functionality and that is admittedly a bit onerous to implement in a RBDMS. Even though I feel like every project needs/requires that eventually.
https://docs.oracle.com/en/database/oracle/oracle-database/2...
You can configure how long the old data is kept:
https://docs.oracle.com/en/database/oracle/oracle-database/2...
Worked examples:
The garbage collection / VACUUM part of an MVCC system is the harder part, saving all versions and querying a point in time is the easy one.
It is available as PDF on his publications page:
Each time the company was more comfortable with mainstream dbs, so we ended going with something like you’re talking about, built on top of a db. A couple of the projects were because a mainstream dbs wouldn’t scale.
The systems definitely worked, but it was also a lot of implementation complexity on an other wise simple business prop: “store this data as facts”