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0 pointsdkersten5y ago0 comments

> If you have a monolith, now you’ve got a distributed system.

You already did, you just chose to ignore that the DB is actually a separate service. Ignoring this has meant that I've spent a not-insignificant amount of time in my last few jobs cleaning up bad ORM code because the queries performed terribly. I've cleaned such messes as pulling in all rows and then looping/filtering on them client-side, just generally querying for too many things/too many columns, querying for data and then looping over it to do more queries (instead of figuring out how to do it in a join), etc. When people treat the database as if its part of your monolith, because all the query logic is locally part of your codebase in your ORM, there's a temptation to be lazy and treat it that way. And it works fine in development because the database is small with only test data, but can be painfully slow in production.

I'm sure plenty of people do it properly, even with an ORM, but I've had to clean up the mess too many times now, across multiple companies and dev teams.

I'm not advocating for putting all of this logic into stored procedures, I think that's going too far in the other direction, only that you already have a distributes system, if you have a database, where the boundaries do matter.

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AmericanChopper5y ago· 1 in thread

Not to nearly the same degree. Start transaction > mutate data > end transaction is not nearly as distributed as invoke SP > let the database do something (?...) > wait until it's done. The first is a distributed system in the same way that an application writing to a filesystem is a distributed system.

I'd also point out that ORM is not the only alternative to stored procedures. In addition to that, there's nothing unique about ORMs that make them susceptible to bad code, or poor SQL understanding. Somebody who doesn't understand data structures and how the CBO works is going to write equally poor stored procedures. Removing the ORM is not the solution to your engineer not know how RDBMSes work. ORMs also don't suit every use case, but again, having a bias against ORMs is not the solution to failing to understand how your use case fits in with your RDBMS.

dkerstenOP5y ago

> I'd also point out that ORM is not the only alternative to stored procedures.

Absolutely. I personally use HugSQL[1], so no ORM, but I also don't use stored procedures. I guess my main point is that the boundary between application and database matters and not putting logic in the database doesn't make that boundary go away (putting logic in the database also doesn't make it go away). But I take your point, its not to the same degree.

> there's nothing unique about ORMs that make them susceptible to bad code, or poor SQL understanding.

I think that there is: it makes database code look like client-side application code, so there's some temptation to just blur the boundaries and mix them together. This is how you end up with code that queries for data, then does looping and filtering outside of the query, then queries some more. Sure, you can write equally bad code in stored procedures, but the boundaries are more obvious. At the very least, its likely a different programming language from the rest of your application.

> Removing the ORM is not the solution to your engineer not know how RDBMSes work.

Sure, however, in practice, at least in my experience across multiple teams and companies, education hasn't been a reliable solution. People still abuse the ORM and treat it as if the database is magic. Removing the ORM doesn't automatically fix it, of course, but it does force people to consider the database as a separate service whose access crosses a boundary. In an ideal world, everyone already keeps this in mind and ORMs can be used as they were intended, but, at least in my experience, this just hasn't been reality. Have I just been unlucky?

If different people and teams keep making the same mistakes with the tools, maybe its time to re-evaluate the tools and what they encourage people to do. Its not that the tools are bad in and of themselves, but that they encourage bad usage. (EDIT: I just saw another article on the front page and the title seems apt: "Discipline Doesn’t Scale")

[1] https://www.hugsql.org/

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