Does quantum mean its thread safe?
The word quantum doesn't mean thread-safe. But it is thread-safe, since it's fundamentally based on a durable ACID Transaction journal. All the threads in your application can agree on state.
Amazon Quantum Ledger Database
141–150 of 183 posts
Re: Amazon Quantum Ledger Database
#142Earlier quoted context omitted.
Yes, I do. I trade derivatives without the need of a broker. I can also lend DAI to anyone in the world through a smart contract.
It's still too early for most people to understand how amazing the concept around MakerDAO and DAI actually is. They will, but it will take a bit of time.
Been hearing about it but must admit I don't fully understand it. Would you mind a sentence or two on why the concept is so amazing?
Re: Amazon Quantum Ledger Database
#143I'm pretty sure this is what most people actually want when they say they want a blockchain, they just don't know it yet. It's got all the useful database features with none of the "well uh let's distribute it over people's computers and let people mine coins to support it" complexity, which adds nothing to 99% of usecases besides silly ICO potential.
How can you make something like MakerDAO on a centralized ledger?
I don't think anyone is arguing that you can. But most companies who want a ledger don't need a blockchain to accomplish it.
In your case, you're talking about no trusted actors in a very decentralized system. We're talking about walmart tracking supply chain and whatnot.
For a centralized ledger where you do have trusted actors, blockchain is a hilariously shitty solution.
Re: Amazon Quantum Ledger Database
#144Earlier quoted context omitted.
Inmutability of the transaction history.
You don’t need a blockchain for that also if the “transcation data” itself is not immutable such as in the case of a banana so how would this work exactly?
The transaction data should be immutable; many of the actual facts concerning the Banana are not mutable: it was picked when it was picked, it was moved when it was moved. Assuming the transactions reflect this accurately, they need not be mutable. What the transaction data should not be is irreversible. So, for example, if there's a data entry error discovered, I need to show that I'm changing the current knowledge of that banana without losing the prior erroneous transaction. It's the same sort of thing we'd do for a financial ledger: we don't change existing erroneous records in the database... we book new correcting records.
In a number of your comments you talk about errors: the transaction processing technology being discussed will not address those issues be they mistakes, non-compliance, or anything other that rather naive cheating.
I think people hear about some of the attributes of blockchain, such as being distributed, and say, "hey, that solves some of the problem of getting disparate, unrelated parties transacting in a common data set."... along with a misunderstanding of trust model and its relationship to data integrity across that shared ledger... and they get all excited about blockchain.
You're right you don't need blockchain and a central database could do it. The harder parts are administrative around the many parties and then getting the parties to participate at all. I think the transnational immutability aspects are beneficial for food safety, I don't think the raw complexity of implementing a new blockchain to do it makes sense.
I do think with the right kind of industry focused solution on top of something like this Amazon product, can be that sort of single database, with some of the helpful parts that have appeal in regards to blockchain and without the complexity. There are still issues which I don't believe something like this Amazon product solves, but I do think it moves the needle.
Re: Amazon Quantum Ledger Database
#145Am I right in believing this looks like a competitor to Datomic?
Datomic doesn't have cryptographically-guaranteed immutability -- its logical data model is immutable and so you can query the past versions of data etc., but there isn't anything stopping one from altering the history. In a ledger like this, history cannot be modified (assuming reasonable computational limits). Datomic also has much richer data model and query languages.
Re: Amazon Quantum Ledger Database
#146Newbie here. Questions: 1) Can somebody go over use cases and target customers, where one would prefer this over more traditional DBs. 2) Since this is centralized, it is in theory possible to go back to a previous state of the ledger. Is that blocked simply because the product doesn't support rolling back to a previous state?
1: Use case. Traditional bookkeeping. Asset account balances start at zero initially, then increase with every debit and decrease with every credit. If someone mis-reads a check and enters a deposit as $200 instead of as $20, we do not change the $200 to $20. Instead, we do one of two things: reverse the difference with a $180 credit, or reverse the deposit with a $200 credit followed by a new $20 debit. Traditional DBs support all three approaches: reverse and repost, reverse differences, change the original. If you need to know why the original was changed, in a traditional DB you need an additional audit trail. Implementers can neglect to implement a n audit table. With QLDB, there is no risk that the implementers will choose to update the original deposit, because the database is write-once.
Re: Amazon Quantum Ledger Database
#147Earlier quoted context omitted.
Do you know if the QLDB write API is more like an event store or more like a relational database? It sounds like the read API provides both models (read the journal, or read the snapshot).
It should work for both cases. It's an append-only ledger that captures any mutations on records previously on the ledger. It uses a recent snapshot primarily for efficiency to avoid having to read the entire ledger to enforce any transactional or schema constraints. So it's an event store in that each write transaction is an event. But it's a relational DB in that it (at least the internal version did) schemas, mult…
That's an understandable implementation, but a bit disappointing. It means that there's not going to be a simple way to process the journal since that log will consists of differently sized writes to the database. It would have been more interesting if QLDB was a CQRS+EventStore with built-in snapshots.
Re: Amazon Quantum Ledger Database
#148I'm pretty sure this is what most people actually want when they say they want a blockchain, they just don't know it yet. It's got all the useful database features with none of the "well uh let's distribute it over people's computers and let people mine coins to support it" complexity, which adds nothing to 99% of usecases besides silly ICO potential.
Actually, I'm pretty sure most people don't have a clue when it comes to blockchain. Amazon can't claim it is both centralized and immutable. That's complete nonsense. Also WTF is the point of a blockchain if you need to entrust your ledger data to a third party? Amazon puts out some spectacular products and innovation, but this one is laugh out loud material.
> Amazon can't claim it is both centralized and immutable.
Amazon can claim it is both centralized and immutable, provided you trust Amazon.
> Also WTF is the point of a blockchain if you need to entrust your ledger data to a third party?
Maybe none? I might be willing to bet that 99% of blockchains in use today could in fact just use AQLD or similar.
And this is what it comes down to: most of us live in a world where trust can, and does, have to root out somewhere. So much of our society is built around this. Blockchains feel sort of alien in this world.
Re: Amazon Quantum Ledger Database
#149Why are they using the word "quantum" here? With the advent of actual quantum computing this will just become increasingly confusing.
Re: Amazon Quantum Ledger Database
#150This reminds me of temporal database [1] concepts. I've been thinking that besides the hashing aspect of it, otherwise, it's actually basically the same as a temporal database, isn't it?
I do like that they referred to it as a database rather than blockchain, as it more accurately captures the fact that it is a data store and I always felt like blockchain was more a reference to the way that the data is cryptographically linked together in the data store.