Where database blog posts get flame-broiled to perfection
Ah, another dispatch from the "move fast and break things" contingent. A student, bless their earnest heart, forwarded me this... promotional pamphlet about using a chatbot to perform database tuning. It seems we've reached the point where the industry has decided that decades of research into cost-based optimization were simply too much reading. One must admire the ambition, if not the intellect.
Let us deconstruct this... AI-powered innovation.
First, we have the sheer audacity of applying a Large Language Modelâa tool designed for probabilistic text generationâto the deterministic, mathematically precise field of query optimization. The query planner is one of the great triumphs of computer science, a delicate engine of calculus and heuristics. Entrusting it to a system that hallucinates legal precedents and can be convinced it's a pirate is, to put it mildly, an affront to the discipline. One shudders to think what Edgar Codd, a man who built an entire paradigm on the bedrock of formal logic, would make of this statistical parlor trick.
They then announce, with the breathless wonder of a first-year undergraduate, their "discovery" that one should analyze the workload to suggest indices. They proudly state:
...we typically look for query patterns with a high ratio of rows read to rows returned.
Groundbreaking. This is akin to a physicist announcing that objects, when dropped, tend to fall downwards. Clearly they've never read Stonebraker's seminal work on Ingres, let alone Selinger and Astrahan's paper on System R's optimizer from 1979. Perhaps those weren't included in the web scrape used to train their model.
Then comes the "most crucial step: validation." And what is this robust, high-stakes process? They run EXPLAIN with a hypothetical index. That's it. They are taking the planner's cost estimateâan educated guess, subject to stale statistics, cardinality misestimations, and a dozen other known failure modesâand treating it as gospel. This is not validation; it is a desperate hope that the black box isn't lying this time. For a system that should, presumably, exhibit the Consistency and Isolation of ACID, relying on a non-deterministic suggestion followed by an estimated confirmation is terrifying.
This entire endeavor fundamentally misunderstands the holistic nature of a database schema. An index is not a simple performance patch; it is a structural change with profound implications for write performance, storage, and the operational cost of every INSERT, UPDATE, and DELETE on that table. The casual suggestion of new indices ignores the delicate balance of the system. It's a classic case of chasing a local maximumâfaster SELECTsâwhile blithely courting a global catastrophe of write contention and lock escalation. It reveals a worldview where the CAP theorem is not a fundamental trade-off to be reasoned about, but an inconvenient footnote.
Still, one must... applaud the effort, I suppose. It's a charming attempt to automate a task that requires deep, foundational knowledge by throwing a sufficiently large matrix multiplication at it. A valiant, if deeply misguided, effort.
Now, if you'll excuse me, I have actual papers to reviewâdocuments with proofs, not prompts.