A database is not only about disk size and query performance. Database reflects the company's culture, processes, workflows, collaboration etc. It has an entire ecosystem around it - master data, business processes, transactions, distributed applications, regulatory requirements, resiliency, Ops, reports, tooling etc,
The role of a database is not just to deliver query performance. It needs to fit into the ecosystem, serve the overall role on multiple facets, deliver on a wide range of expectations - tech and non-tech.
While the useful dataset itself may not outpace the hardware advancements, the ecosystem complexity will definitely outpace any hardware or AI advancements. Overall adaptation to the ecosystem will dictate the database choice, not query performance. Technologies will not operate in isolation.
And its very much the tech culture at large that influences the company's tech choices. Those techies chasing shiny things and trying to shoehorn it into their job - perhaps cynically to pad their cvs or perhaps generously thinking it will actually be the right thing to do - have an outsized say in how tech teams think about tech and what they imagine their job is.
Back in 2012 we were just recovering from the everything-is-xml craze and in the middle of the no-sql craze and everything was web-scale and distribute-first micro-services etc.
And now, after all that mess, we have learned to love what came before: namely, please please please just give me sql! :D
Why you don't just quietly use SQL instead of condescending lecturing others about how compromised their tech choices are.
NoSQL e.g. Cassandra, MongoDB and Microservices were invented to solve real-world problems which is why they are still so heavily used today. And the criticism of them is exactly the same that was levelled at SQL back in the day.
It's all just tools at the end of the day and there isn't one that works for all use cases.
Around 20 years ago I was working for a database company. During that time, I attended SIGMOD, which is the top conference for databases.
The keynote speaker for the conference Stonebraker, who started Postgres, among other things. He talked about the history of relational databases.
At that time, XML databases were all the rage -- now nobody remembers them. Stonebraker explained that there is nothing new in the hierarchical databases. There was a significant battle in SIGMOD, I think somewhere in the 1980s (I forget the exact time frame) between network databases and relational databases.
The relational databases won that battle, as they have won against each competing hierarchical database technology since.
The reason is that relational databases are based on relational algebra. This has very practical consequences, for example you can query the data more flexibly.
When you use JSON storage such as MongoDB, when you decide your root entities you are stuck with that decision. I see very often in practice that there will always come new requirements that you did not foresee that you then need to work around.
MongoDB is a $2b/year revenue company growing at 20% y/y. JSON stores are not going anywhere and it's an essential tool for dealing in data where you have no control over the schema or you want to do it in the application layer.
And the only "battle" is one you've invented in your head. People who deal in data for a living just pick the right data store for the right data schema.
"Battle" was (if I remember correctly) the term used by Stonebraker in his 2001 SIGMOD keynote to describe what happened at that specific SIGMOD in the 1980s. It is not "only in my head". Like I said, I don't care what other people store data in.
I don't think MongoDB is going anywhere on the medium term, and there is always going to be some customers. Just like the network databases in the 70s, or XML databases in the 90s.
Bad ideas never die, they just resurface in another form, which people label as "new".
Every person I know who has ever used Cassandra in prod has cursed its name. Mongo lost data for close to a decade, and Microservices mostly are NOT used to solve real world problems but instead used either as an organizational or technical hammer for which everything is a nail. Hell there's entire books written how you should cut people off from each other so they can "naturally" write microservices and hyperscale your company!!
Whereas the fact is that Datastax and MongoDB are highly successful companies indicating that in fact those databases are solving a real world problem.
That wasn't his point. His point is that a company being successful is evidence of nothing. Plenty of companies are successful and make shit products, often on purpose. There's a whole sleuth of companies that have the entire business venture of "do what X does but shitter". And they make a lot of money.
So, if your evidence is "well MongoDB makes money" then that doesn't mean much.
No, a database reflects what you make out of it. Reports are just queries after all. I dont know what all the other stuff you named has to do with the database directly. The only purpose of databases is to store and read data, thats what it comes down to. So query performance IS one of the most important metrics.
The role of a database is not just to deliver query performance. It needs to fit into the ecosystem, serve the overall role on multiple facets, deliver on a wide range of expectations - tech and non-tech.
While the useful dataset itself may not outpace the hardware advancements, the ecosystem complexity will definitely outpace any hardware or AI advancements. Overall adaptation to the ecosystem will dictate the database choice, not query performance. Technologies will not operate in isolation.