Quote from: doof on November 27, 2016, 04:39:08 AM

Yes, I used MS SQL for a project www.blockchainsql.io. 450GB database. If you optimise right, queries can be lightning fast.

Cool. Is that your project or did you build a project that used the mentioned project as something like an API?

At a 450-GB DB I think queries could be optimized up to less than 1 minute speed with your home gaming PC.

Quote from: CIYAM on November 27, 2016, 05:20:01 AM

Quote from: PremiumCodeX on November 26, 2016, 09:34:53 PM

Correct me if I misunderstood something, but would not that require a MUCH bigger size of HDD?

As deletion (and in Bitcoin rollbacks) are infrequent operations it wouldn't practically be as significant an increase as you are imagining (but it would use more space for the translation log).

Quote from: PremiumCodeX on November 26, 2016, 09:34:53 PM

In addition, the log writing and reading speed would significantly increase that would result in slower DBs, would not it? At large DBs, speed is essential because some queries could take up to 20 or more minutes even without the mentioned idea.

Normal RDBMS "queries" do not involve the log at all so it would not have any speed effect upon read operations (it would only slow down "delete" operations).

It depends on the use-case then because in some DBs there are frequent delete operations. But I agree that most DBs are not like that so the possibility is worth to take into consideration. The question is how much it would increase the necessary space and the issue of SRP because even though rollbacks are infrequent operations, when they need them they usually need them ASAP.