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Comment by colllectorof | Hacker News Reader

SQL Server and Oracle have different features and idiosyncrasies, but use the same fundamental models of data storage that is a product of decades of research and development and isn't controlled or promoted by a single company. You're not going to suddenly run into some fundamental limitation that will suddenly fuck you over on architectural level.

This happens all the time with databases like Dynamo. All of them feel amazing when you use them in the "intended" way, but they also have extreme limitations and those limitations are different for every product. Why? Because they aren't based on some fundamental data storage model, but rather on an aggregation of specific use cases, which are different across different products.

Here is a mild practical example: https://blog.codebarrel.io/why-we-switched-from-dynamodb-bac...

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Dynamo, like many NoSQL dbs, is (partition key, subkey, value). Partition key gets you to a storage node. Subkey gets you range queries on that storage node. That's the "fundamental data storage model" for most of NoSQL. And it's extremely useful for some use cases.

You could have mapped your use case to this storage model and gotten ridiculously fast queries on vast mountains of data, which is largely the point of NoSQL. But this would have required data duplication, home-made management tools for dealing with said data duplication, and other work that was clearly better spent implementing the much simpler SQL solution.

A benefit of the SQL approach is that if your queries start getting bogged down from growth in data size and/or request volume (not entirely unexpected behavior when you have a couple joins), you can move to a different model where you treat the SQL db as a slow-access source of truth and periodically generate key/value into NoSQL or Redis/ES/etc for actually running queries.

I’m very well aware of that. If they thought about using DynamoDB and they did even cursory research, they would know that it’s basically a glorified key value store with the chance of using multiple key value types - ie global and local indexes.

There are certain (limited) use cases where it is good. Every technology choice takes you down a certain road and limits your implementation choices in certain ways. It’s not the fault of the tool if they choose one that doesn’t meet their needs.

Also, the beauty of something like AWS, is that you can do “polyglot persistence”. You can have different services in your infrastructure use different types of storage depending on the use case.

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