Comments on: Stonebraker and the CAP Theorem

By: Nathan Fiedler

Nathan Fiedler — Fri, 20 Nov 2009 16:27:53 +0000

Thanks for writing this post. Since reading Stonebraker’s biased article I’ve wanted to write my own critique. What’s interesting is how he avoids any specifics and clearly ignores the flip side of the coin: the benefits you gain when making different choices. Dynamo (and it’s ilk) and Bigtable/HBase have a lot to offer and Stonebraker didn’t address that at all.

It should be noted that Stonebraker has a vested interest in spreading the FUD on NoSQL.

By: Jeff Darcy

Jeff Darcy — Wed, 18 Nov 2009 11:45:42 +0000

Good points, Sean. I shouldn’t have said “abandon C” above; having made the same point myself in multiple presentations, I should know better. Thanks for the reminder.

By: Sean

Sean — Wed, 18 Nov 2009 04:42:15 +0000

Great article!

An interesting point that Justin Sheehy (@justinsheehy) made in his talk to no:sql(east) was that sacrificing consistency doesn’t mean you have license to lose data – just that you may not have the same version of data at all points in your system at all times. I think “data loss” is what people deep in OnlySQL think when they hear “eventual consistency”. He also told me in a private conversation that in the case of Riak and some other Dynamo-inspired stores, “eventual consistency” means milliseconds – not seconds or minutes.

Also, he points out that CAP is not “pick two”, it’s “know your tradeoffs”. Riak and Dynomite are interesting because they let you choose which tradeoffs to make and tune the system to your application’s needs. Riak even lets you make some choices at runtime.