The property you are looking for - that every SQL command can take place in a transaction - is surely a very desirable property for a SQL database to have, but

The property you are looking for - that every SQL command can take place in a transaction - is surely a very desirable property for a SQL database to have, but from my perspective a database can provide genuine ACID transactions even if it only supports a subset of read and write operations within them. Actually, I think we are giving too much credit to Oracle! There are (relatively subtle, but real) concurrency anomalies in their so-called "serializable" isolation level.