🔥 The DB Grill 🔥

Alright, let's pull up a chair. I've just finished my third cup of lukewarm coffee from the breakroom, and my disposition is, shall we say, optimized for fiscal scrutiny. And what do I find in my inbox? An article titled "Normal Forms and MongoDB." Oh, splendid. A philosophical treatise on how to reinvent the wheel, but this time, make it square and charge us for the patent.

The core thesis seems to be that normal forms aren't just for crusty old relational databases, and that MongoDB's "flexibility" lets you apply them thoughtfully. Let me translate that from marketing-speak into CFO-speak: "We've shifted the multi-million-dollar responsibility of data integrity from our product directly onto your payroll."

It all starts so innocently, doesn't it? A little pizzeria, an MVP. “You can choose any database for this… even a spreadsheet.” See, that’s the hook. They get you comfortable. They whisper sweet nothings about starting small. It’s the enterprise software equivalent of a free popcorn machine at a car dealership. You’re not here for the popcorn, son, and that "simple" key-value store is the undercoating package you never wanted.

Then, the "business evolves." Of course it does. And with it, our simple JSON object begins to look like a Christmas tree after a tinsel-and-update-anomaly explosion. Suddenly we’re hand-wringing about 1NF and arrays. But don’t worry! MongoDB is here to help, letting us use arrays instead of comma-separated strings. Groundbreaking. My TI-83 calculator from college could do that. The key phrase here is that MongoDB keeps data "colocated for more predictable performance." Predictably slow, that is, once we have to scan a million 50MB documents to find out which pizzeria sells a gluten-free calzone.

But this is where the real fun begins. We get to 2NF and the pricing problem. If prices are standardized, we have a "partial dependency." The relational world solves this with a simple table and a join. But no, that’s for dinosaurs. In our brave new world, we have two enlightened options:

• Create a "view" with a five-stage aggregation pipeline that looks more complex than my last tax return. I can already hear the servers screaming and the cloud bill ticking up like a taxi meter in rush hour.
• Or my personal favorite: duplicate the price everywhere and then—get this—write a custom, multi-document, acid-compliant transaction in the application code every single time a price changes.

Let's do some quick math on that, shall we?

The application is responsible for maintaining consistency.

That one sentence is the most expensive piece of prose I've ever read. Let's call it the "Application Responsibility Tax." I see:

• Developer Hours: 40 hours for two senior engineers to build the initial price update service. That’s about $8,000, just to start.
• QA & Testing: Another 20 hours to make sure this Rube Goldberg machine doesn't accidentally set all pizza prices to zero. We'll call that a conservative $3,000.
• Inevitable Consultant: When it breaks during the Super Bowl rush, we'll need a "MongoDB Certified Professional" at $450/hour to fly in and tell us our arrayFilters are wrong. Let's budget a week for that, so... $18,000.
• The "We Messed Up" Write-Down: The cost of lost revenue and customer refunds when an update fails halfway through and half our pizzas cost $11 while the other half cost $10. Let's call it a cool $50,000 learning experience.

So, this "flexibility" of violating 2NF has cost us $79,000 and a migraine before we've even gotten to toppings. And the author dares to suggest this is acceptable because "price changes are infrequent." A statement clearly written by someone who has never met our marketing department.

And it just gets better! We waltz through 3NF, where we solve a "transitive dependency" by... nesting a JSON object. Brilliant. Then 4NF, where we learn that having two independent arrays is better than a Cartesian product of redundant data. I am truly stunned by this revelation.

But BCNF is where the mask fully slips. We have an "area" that determines an "areaManager." A clear violation. The relational solution? A separate table. Clean. Simple. The MongoDB solution? "Handle updates explicitly." They even provide the updateMany script, as if to say, “See? It’s just one little command!” They conveniently forget to mention that this command will lock collections, run for an hour on a large dataset, and has to be manually triggered by a developer who we now have to pay to be a human join-engine.

By the time we reach 5NF and 6NF, we’re storing price history and decomposing everything into independent arrays and separate collections. We've spent this entire article twisting a document database into a poor man's relational model. We're using $lookup, application-level transactions, and manual update scripts to avoid the one thing that was designed to solve these problems from the start.

This isn’t a database; it’s a kit car. It looks flashy, but it arrives in 500 pieces, the instructions are in a language you don’t quite understand, and you’re left to assemble it on your weekends with duct tape and hope.

The conclusion is the cherry on top of this fiscal disaster sundae. They talk about Domain-Driven Design, CQRS, and microservices. These aren't architectural patterns; they're incantations used to justify astronomical development budgets. "The database is not a shared integration point but a private persistence detail." Wonderful. So now instead of one database to manage, we have 50 "persistence details," each with its own bespoke integrity model written by a different team. That's not a feature; that's a long-term liability that I'll be amortizing over the next decade.

Let's calculate the "True Cost of Ownership" for this pizzeria empire. The sticker price for the database is, say, $250k a year. But the real price is:

• $250k (License)
• • $1M/year (for the five extra senior developers needed to be "application-level D.B.A.s")
• • $300k/year (for the QA team that now has to test for data anomalies in every single service)
• • $200k/year (for the "inevitable consultant" retainer)
• • $1.5M (one-time migration cost to a sane database in three years when this all collapses)

Total cost for this "flexibility": A $3.25 million bonfire. And for what? So our developers can feel like they're working in a modern architecture? I’d get a better ROI by buying actual pizzerias.

So thank you for this enlightening post. It has helped me normalize my vendor list right into the recycling bin. Rest assured, I will not be reading this blog again. I have a P&L to protect.