The "give everybody a 10% raise" case can be looked upon either as a bug or a feature. Sometimes it's nice that anybody can do anything; sometimes it isn't.
As to creating the infrastructure and worries about reliability, there are a number of frameworks for this. E.g., Prevayler. It gives you all the ACID guarantees, but has about three orders of magnitude less code than a modern database.
Supporting it could definitely be a problem. That's true for anything novel, so I'd only do this where the (major) performance benefits outweigh the support cost.
Some kinds of statistics are easier with this. For example, if you want to keep a bunch of up-to-date stats on stocks (latest price, highs, lows, and moving averages for last hour, day, and week) it is almost trivially easy in a NoDB system, and much, much faster than with a typical SQL system.
For other stats and reporting, though, dumping to an SQL database is great. For many systems you don't want to use your main database for statistics anyhow, so a NoDB approach mainly means you start using some sort of data warehouse a little earlier.
As to creating the infrastructure and worries about reliability, there are a number of frameworks for this. E.g., Prevayler. It gives you all the ACID guarantees, but has about three orders of magnitude less code than a modern database.
Supporting it could definitely be a problem. That's true for anything novel, so I'd only do this where the (major) performance benefits outweigh the support cost.
Some kinds of statistics are easier with this. For example, if you want to keep a bunch of up-to-date stats on stocks (latest price, highs, lows, and moving averages for last hour, day, and week) it is almost trivially easy in a NoDB system, and much, much faster than with a typical SQL system.
For other stats and reporting, though, dumping to an SQL database is great. For many systems you don't want to use your main database for statistics anyhow, so a NoDB approach mainly means you start using some sort of data warehouse a little earlier.