Yugabyte's double-decker DBaaS follows Cochroach in distributed RDBMS

Distributed relational database Yugabyte has launched a database-as-a-service product following a rush of inspiration from Facebook, Google and the world of FOSS. While the open-source DBaaS impressed one analyst, it will have to cope with competition from well-funded CockroachDB, which has had its DBaaS on the market for …

[spold]

Nobody has commented yet because they are still trying to parse and decode it.

[Gene Cash]

I got buzzword bingo so I had to go cash in my card

[Anonymous Coward]

No

Everyone is still wondering how it's been a week since 150 gigabytes of Epik customer data was dumped on the web and The Register still doesn't have any articles about it. Epik long has been the favorite Internet hosting company of the far-right, providing domain services to QAnon theorists, Proud Boys and other instigators of the Jan. 6 attack on the U.S. Capitol. Data from the Epik hack leak reveals subpoenas and preservation requests directed to the company for information about some of its customers, apparently issued in the wake of Jan. 6.

https://techcrunch.com/2021/09/17/epik-website-bug-hacked/

https://www.washingtonpost.com/technology/2021/09/21/epik-far-right-hack-anonymous/

https://www.dailydot.com/debug/epik-hack-subpoenas-data-preservation-leak/

[W.S.Gosset]

Kimball...

Takes me back. Galactic Patrol, Grey Lensman etc.

[W.S.Gosset]

Relational?

They're both talking like standard 3GL-style people, especially when they imply their idea of relational is SQL as a language. Does anyone have any insight into both or either of their underpinnings' actual relational capacity? Not just whether transactions are genuine, but critically their isolation levels. Precious few rdbms's can manage full isolation/predicate locking (e.g. Oracle needs to be shut down and restarted with a special setting, after which its locking granularity is Table...)

[Robert Grant]

Re: Relational?

It's hard to know your point here - are you saying they should have a non-3GL perspective, e.g. a 4GL language? When do they imply their idea of relational is SQL as a language?

[Crypto Monad]

Re: Relational?

A simple google search for "yugabyte isolation levels", and the first three hits should answer in sufficient detail.

YugabyteDB supports two transaction isolation levels - SERIALIZABLE (which maps to the SQL isolation level of the same name) and SNAPSHOT (which is mapped to the SQL isolation level REPEATABLE READ). Thus, YugabyteDB supports the two strictest of the above four isolation levels.

[W.S.Gosset]

Re: Relational?

Thanks for that. Sorry, it was late and I was just bimbling on my phone with my brain at half-mast. Now it's early and I'm nursing a coffee.

You pointed me at https://docs.yugabyte.com/latest/architecture/transactions/isolation-levels/ .

So, sadly, it appears it does NOT do full serialisation. No predicate locking, only locking of existing data. That is, it can not protect against changes in scope intra-transaction. Or rather: increases in scope -- decreases will be blocked. So: not SQL-92 compliant. (Very few "r"dbms's are) Oh well.

Of graver concern is the implication that the isolation management is not handled by the engine. It's handled by the interface layers. Note the distinction between the YSQL and YCQL APIs. Different codebases replicating the same functionality ... there's a maintenance nightmare waiting to happen. I remember Sybase ran that route for speed, different tweaked codebases for different query plans, and some were buggy: you could alter say the order of your tablelist and trigger a Cartesian product. Eurgh. I banned Sybase in our Sydney office when I discovered that.

[Robert Grant]

Re: Relational?

I think Spanner achieves this by having atomic clocks, and making minimum transaction time guarantees that take long enough for signals to reach all nodes. Cockroach and Yugabyte are simpler, and so can't offer that guarantee, but are still pretty useful for lots of workloads.

[datamgmt]

Re: Relational?

Hi Robert

I know a bit about Yugabyte - the base design is inspired by Google Spanner, but with the added advantage of a PostgreSQL compatible interface - specifically, because it uses the PostgreSQL v11.2 query layer.

There is a great article about how an Atomic Clock can be replaced by a Hybrid Logical Clock https://www.yugabyte.com/wp-content/uploads/2021/05/Distributed-Transactions-Without-Atomic-Clocks.pdf

The added advantage of this approach is that it can be used cross-cloud and hybrid on-prem/cloud as it doesn't rely on a specific atomic clock configuration but has the same minimum transaction time guarantees.

Best

David