nosql comparison: All content tagged as nosql comparison in NoSQL databases and polyglot persistence
From the Amazon ☞ Migrating your Existing Applications to the AWS Cloud paper (PDF):
- What are the different storage options available in the cloud today?
- What are the different RDBMS (commercial and open source) options available in the cloud today?
- What is my data segmentation strategy? What trade-offs do I have to make?
- How much effort (in terms new development, one-off scripts) is required to migrate all my data to the cloud?
When choosing the appropriate storage option, one size does not fit all (nb: my emphasis). There are several dimensions that you might have to consider so that your application can scale to your needs appropriately with minimal effort. You have to make the right tradeoffs among various dimensions - cost, durability, query-ability, availability, latency, performance (response time), relational (SQL joins), size of object stored (large, small), accessibility, read heavy vs. write heavy, update frequency, cache-ability, consistency (strict, eventual) and transience (short-lived).
Just replace the words “cloud” and “AWS” with NoSQL database and you get a good base for your migration plan.
Interesting article from Xeround Avi Kapuya ☞ NoSQL: The Sequel. Couple of comments though:
In other words, in SQL, the data model does not enforce a specific way to work with the data — it is built with an emphasis on data integrity, simplicity, data normalization and abstraction, which are all extremely important for large complex applications.
I’d say that data normalization is not a goal per se, but a solution to a problem (data duplication, frequent updates to common entities). But what if this solution is introducing another bigger problem (read JOINs)?
The NoSQL approach presents huge advantages over SQL databases because it allows one to scale an application to new levels
Plus it may give you more flexibility in your data model, plus it may be a better (as in operational, complexity, performance, etc.) storage for different formats of data.
Why not NoSQL
At the system level, data models are key*. Not having a skilled authority to design a single, well-defined data model, regardless of the technology used, has its drawbacks.
Actually I think the reality might be a bit different. Because NoSQL imposes a “narrow predefined access pattern” it will require one to spend more time understanding and organizing data. Secondly, the final model will reflect and be based on the reality of the application, on not only on pure theory (as is the case with most initial relational model designs).
At the architecture level, two major issues are interfaces and interoperability. Interfaces for the NoSQL data services are yet to be standardized.
The interface limitation is a temporary issue in terms of getting more/better/quicker tooling support and probably a longer term issue for developers needing to learn different models. But as we’ve agreed, NoSQL has a small, predefined access mode and so we are not talking about learning completely new languages.
Personally, I think the real issue is steep learning curve of understanding each of these NoSQL databases semantics and operational behavior then not having a common API.
Interoperability is an important point, especially when data needs to be accessed by multiple services.
I’m not seeing the problem here. As far as I know each relational database is coming with its per-language drivers. On the NoSQL side, there are already quite a few products using standard protocols.
Moving to the operational realm, here, from my experience, lies the toughest resistance, and rightfully so… The operational environment requires a set of tools that is not only scalable but also manageable and stable, be it on the cloud or on a fixed set of servers. […] Operation needs to be systematic and self contained.
Now, this is completely the other way around. If you read any large scale application story, you’ll notice the pattern: the operational costs where a significant factor in deciding to use NoSQL. Just check the stories of Twitter, Adobe, Adobe products, Facebook. Complexity is a fundamental dimension of scalability and right now the balance is towards NoSQL databases .
It is my opinion that a SQL database built on NoSQL foundations can provide the highest value to customers who wish to be both agile and efficient while they grow.
Unfortunately I don’t think that’s actually possible or at least not for all solutions. But If we just want some common access language, we will probably get it.
If, on the other hand, what we want is more tunable and scenario specific engines, we will probably get these too. (nb: as far as I’ve heard the PostgreSQL community is learning a lot from the various NoSQL databases and trying to bring in as many of the good ideas they can).
My conclusion is simple. As with programming languages where we are not stuck with COBOL, polyglot persistence is here to stay and it’ll only get better.