Hipkiss if you want to get into semantics, even S3 could be considered a database for storing information. You could make a simple JSON based database out of S3. But the point is not to do that.

Writes to blockchains are very slow due to the inherent nature of authenticating each record before inserting. Modification is not possible, only new updates can be added to the chain which further increase the read time for a particular "record" or "document", as you'll have to read the whole chain to determine the actual value.

A "store of information" is too broad a definition for a database. A physical ledger will be a database, every hard disk will be a database, anything recorded anywhere ever would be a database. And if we go by that rule, then yes, blockchain is a database.

Sidhant Panda Agreed, S3 could be considered a DB, as well as everything else you mention. And to be clear, I would never use blockchain the same way I would use a conventional DB, or hard drive or anything else for that matter. I think a closer description of blockchain would be a ledger.

Please can you explain a little more what you mean by reading the whole chain to determine the actual value - value of what? Just so I don't respond with something that you didn't mean :).

*Some blockchains are slow. Verifying a transaction on bitcoin used to take hours. With the new lightening network, it will be closer to 5 - 15 minutes. I know that Ripple (XRP) have a verification time of 3 seconds. It really does vary from crypto algorithm to algorithm.

By saying all blockchains are slow for insertion, I mean compared to databases, not amongst themselves. No matter how fast an algorithm is used to create an entry, there will be some algorithm to follow, which will be the rate limiting step in insertion.

By "value" mentioned before, I meant any related property of the user, could be number of posts by a user, something which is a derived property of user behaviour recorded on the chain. By that, I mean there is no real querying interface to a blockchain, one of the most important features of a DB. It's not just about storing information, but also retrieving it efficiently. Even IBM's Hyperledger uses CouchDB internally to allow efficient querying.

Hence I wouldn't consider blockchain to be a database, neither in a traditional nor in an unconventional sense.

Yes, you can go with SQL.

just to be clear you are aware of the consequences of a blockchain ? :) the memory growth and transaction time is linear all the time? A bank is making millions of transactions a day so they would need Petabytes of data.

Etherium has 200GB after 6 months, and they are pretty slow in comparison. And every party would have to sign everything ;D ... just thinking that 1 troll puts himself behind a 56k modem and what that would mean?

so the consequence of idea behind sharing everything is that you have to share everything and everyone has to agree that is a tedious problem the more things you have to agree on and the more people who have to agree on the slower it will get :)

Just as a thought about the problems of this kind of technology :)

Anuj Sharma Look at ripple.com