🔥 The DB Grill 🔥

Oh, fantastic. Another blog post promising a silver bullet. "Branches in beta." Let me just print this out and frame it next to the "Migrate to NoSQL, it's web scale" memo from 2014 and the "Our new serverless database has infinite scalability" flyer from 2019. They'll look great together in my museum of broken promises.

"Create new branches using real production data... without impacting your production deployment."

Right. I just felt a phantom pager vibrate in my pocket. My eye is starting to twitch. You know what else was supposed to be a simple, zero-impact operation? That one time we moved from Postgres 9.6 to 11. It was just a "logical replication slot," they said. It'll be seamless, they said. I have a permanent indentation on my forehead from my desk, earned during the 72-hour incident call where we discovered the logical replication couldn't handle our write throughput and the primary database's disk filled up with WAL logs. Seamless.

But sure, let's talk about branches. Like Git, but for a multi-terabyte database that powers our entire company. What could possibly go wrong? I can already picture the Slack channels.

• 10:00 AM: A junior dev, bless his heart, creates a "branch" of the production users table to test his new onboarding flow. He calls it josh-test-branch-pls-ignore.
• 10:05 AM: He needs to test the deletion path. He runs a TRUNCATE command. He thinks he's a genius for testing on a branch.
• 10:06 AM: The C-level exec who sold us on this "revolutionary" database platform is on a conference call, boasting about our developer velocity.
• 10:07 AM: We get a page. P1: Authentication Service Latency Skyrocketing. Turns out, "creating a branch" isn't a magical, free operation. It puts a read lock on a few critical tables for just long enough to cascade into a service-wide failure. Or maybe the storage IOPS are saturated from, you know, copying all of production. Who could have possibly predicted that?

...develop and test new features without impacting your production deployment.

This line is my favorite. It has the same delusional optimism as a project manager putting "Fix all technical debt" on a sprint ticket. You're telling me that I can give every developer a full-fat, petabyte-scale copy of our most sensitive PII, and the only thing I have to worry about is them merging their half-baked schema change back into main?

Oh god, the merge. I hadn't even gotten to the merge. What does a three-way merge conflict look like on a database schema? Does the CTO's laptop just burst into flames? Do you get a Git-style conflict marker in your primary key constraint?

<<<<<<< HEAD ALTER TABLE users ADD COLUMN social_security_number VARCHAR(255); ======= ALTER TABLE users ADD COLUMN ssn_hash_DO_NOT_STORE_RAW_PII_YOU_MONSTER VARCHAR(255); >>>>>>> feature-branch-of-certain-doom

I've seen enough. I've seen the "simple" data backfills that forgot a WHERE clause. I've seen the "harmless" index creation that locked the entire accounts table for four hours on a Monday morning. I've seen a "beta" feature corrupt a transaction ID wraparound counter.

This isn't a feature; it's a footgun factory. It's a brand new, high-performance, venture-capital-funded way to get paged at 3 AM. It’s not solving problems, it's just changing the stack trace of the inevitable outage.

Thanks for the article. I'm going to go ahead and bookmark this in a folder called "Reasons to Become a Goat Farmer." I will not be reading your next post.