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0 pointsbrasetvik12y ago0 comments

I can't comment much on MongoDB, but I've written a bit things to keep in mind when considering Elasticsearch as a NoSQL store here: https://www.found.no/foundation/elasticsearch-as-nosql/

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curun1r12y ago· 2 in thread

An interesting read, but I'd disagree with your contention that NoSQL isn't about ACID. When NoSQL databases started coming out, it was really about which CAP guarantee a database chooses to compromise. Traditional SQL databases are either partition-intolerant or become unavailable (for writes) in the event of a partition. NoSQL databases compromise on consistency. If a database is claiming to be NoSQL and have ACID transactions, they've either disproven CAP or aren't part of the new group of distributed, partition-tolerant databases that people have been calling NoSQL. It's been said for a while that NoSQL is a terrible name for that group of technologies and now that we're getting databases with a non-SQL interface but also having consistency guarantees, the name is starting to cause even more confusion.

Side note: Happy Found customer here...you guys have made it much easier to run our ES index!

brasetvikOP12y ago

Thanks for the feedback!

The point of that section is exactly that "NoSQL" (or to make things even more confusing "NOSQL" (Not only) doesn't have a very specific meaning. Some think it rules out ACID, other's don't. Thus, you'll need to know what you need.

And database marketing tend to not be very good at pointing out what they're not good at, or actually deliver what they promise. See also: http://aphyr.com/tags/jepsen

room27112y ago

I'm not sure you have this right. CAP says nothing about ACID - it only mentions consistency.

NoSQL was in large part about precisely what the name implies - giving up relational (SQL) data in exchange for better performance and the ability to have a distibuted store. Yes, part of this is also about being willing to trade off consistency for availability. But Elasticsearch is an example of a NoSQL store which does focus on consistency (in this case at the expense of availability and, to some extent, partition tolerance).

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