171–180 of 337 posts
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Seriously. "As a C developer, I never check exit codes of child processes. We can just enforce it by ensuring child processes don't have bugs"
`malloc` won't fail, right?
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Every time I have seen a database use foreign keys there has been data corruption, because everyone thought foreign keys were declarative and not procedural. Just because you have a foreign key doesn't mean it was always there or that it applied on every transaction. You can turn them off at the connection level and you in fact must turn them off for almost any kind of bulk data load. You should read shlomi's post he…
Maybe shitty toy database systems like MySQL let you disable constraints on a per session basis. A real database system might let you defer them until the end of a transaction—which is the only correct way to operate. Once you commit that transaction, what you put into the system better fucking make sense and it is the job of the database system (and only the database system) to enforce that. Like I said before if yo…
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Foreign key violations are data corruption!!! It violates the rules of how the data relates and can and will screw up any number of things that depend on the rules being enforced. Reporting and bi data might get hosed. Account management might get hosed. Who knows what happens when FK rules are violated because by definition they should never be violated. It puts all applications on top into a undefined state, leadin…
> It violates the rules of how the data relates You're missing an important point, it violates a certain set of rules of how the data relates. That certain set of rules typically makes it easier to write most general data applications. If your rules define a foreign key as optional, you can easily engineer an application around it. Great examples include NoSQL and Ruby duck-typing. In both cases, you infer actions ba…
When posts like these come up, I'd like to remind people that context matters when making technical decisions. What works for large companies with huge scale (GitHub, Google, Facebook) may not work for you. As a counter point to the linked issue, I operate a few small applications. Foreign-keys (and constraints in general) are great at ensuring that invalid data doesn't find its way into your database. Yes, they have…
As someone currently fighting a battle with an LoB application written without foreign-key constraints with hundreds of thousands of rows of corrupted data because of bugs in sprocs that assigned the wrong value to the wrong foreign key column because they were similarly named - THIS! The reply in the GitHub thread we’re talking about makes it clear that they still perform FK validation - it’s just performed in the a…
One of the nice things you get from database FK constraints is when something messes up the data, you get an exception thrown in the code that's messing it up, complete with a backtrace and whatever inputs and timestamps you care to log.
When posts like these come up, I'd like to remind people that context matters when making technical decisions. What works for large companies with huge scale (GitHub, Google, Facebook) may not work for you. As a counter point to the linked issue, I operate a few small applications. Foreign-keys (and constraints in general) are great at ensuring that invalid data doesn't find its way into your database. Yes, they have…
It's a different part of the field of course, but so many people yield opportunity cost chasing some difficult architectural problem that will likely never impact you, and if it does you'll have resources to throw at it.
Many startups won't even have slave production databases, much less have to worry about network distributed sharding, complex caching strategies, database optimization beyond query analysis.
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I think the emphasis there is the word "online". The method you propose might work, but not necessarily well. Catching missing primary keys at the end is a problem because then you have a bunch of data integrity issues to sort out, preventing you from re-applying the constraint, in a live system where apps are relying on the database to do integrity checks, meaning that there's a decent chance that the running system…
Is it even possible to realistically do FK checks in app code? Nobody uses serializable transactions and with other isolation levels I think it's possible to check for FK, it's OK now, insert new row, but another transaction simultaneously deletes that row and both transactions happily commit. It's called phantom read. Probably it's very rare event, but it'll happen.
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I didn't say never care about scale in the early stage. I've found it a more common problem that people in startups are building systems with too much complexity to solve problems they faced at previous employers, in order to "save themselves time" in the future that ends up never coming. There are certainly some technology companies for which scalability is the most important thing - Instagram being the biggest exam…
> YAGNI OK so then does YAGNI apply to investment? Why not let existing firms handle it in the S&P? > YAGNI (continued) over-engineering is definitely a problem, but so is hindsight bias. I think that most non-trivial tech builds involve some smart investments and some dumb ones. It's essentially a portfolio of decisions made in the face of uncertainty. YAGNI is cynicism and hindsight bias, and over-generalization. I…
Yes, don't rebuild your own balanced portfolio or pay someone to "beat the market" for you; just buy a COTS ETF, put it in the server closet and forget about it for a decade.
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In the same vein, I'd like to remind people that you are probably not a "temporarily low-scale big-data company", in the same vein as a temporarily embarrassed millionaire. In lots of cases going for the very long term scalable solution will be an impediment to your growth, and I'd suggest dealing with those issues when the chance that you need them is on the horizon, rather than across the globe. CQRS is one of the…
The biggest issue with CQRS I've seen is people thinking CQRS means you need multiple, duplicate data structures, mappers, a few Kafka topics and a PhD, when IN REALITY all it means is you put methods that return data without modifying it in one interface/class and methods that have side effects in another interface/class - which is really just a good application of interface segregation. Moreover, you now have a gre…
I'm not sure what you experience with CQRS has been but CQRS is not a solution for scale it is a solution for long-term maintenance costs of a growing codebase by enforcing the decoupling of services.