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You're replies in the comments are rude and borderline fanatical in tone. There are two classes of constraints: one being 'this string shouldn't be longer/short

by orf 10y ago

You're replies in the comments are rude and borderline fanatical in tone. There are two classes of constraints: one being 'this string shouldn't be longer/shorter than x' or 'this value should only be between 1 and 10'. The other kind is 'on the first Tuesday of every month only during a full moon can this record be deleted, and only by a user with permission X'. The first can easily be modelled in SQL, the second should be modelled in your app. The first are not arbitrary, the second are. Not hard to comprehend mate. Just because SQL can't model all constraints doesn't mean you should throw it out the window and reach for mongo. Comments like 'none of you understand this because youre not programmers and therefore know nothing' is incredibly insulting. I'm of the opinion that you know nothing, and if you're happy knowing nothing with fellow mongodb users then so be it. Just keep your nonsense away from me thanks.

1879325272 10y ago
This is just a semantics argument which is boring. A number between 1 and 10 on Tuesday is only slightly different. You can say it is not arbitrary, whatever. You have just proved my point. Just in case you forgot the original claim, it was that if you use a SQL database, the constraints are in your database, but if you use mongo, the constraints are in your code. I refuted this by saying that the constraints are also in the code in a SQL database. You have proven the point even further by highlighting that they are even more complex than the constraints in the database. Therefore, saying that it is a great win that a SQL database can do some basic constraints checking is a ridiculous argument because it hardly contributes any benefit due to the fact that even more complex constraints are in the code. So you have not actually contributed anything and I never said you should throw out SQL just because it can't model every constraint. Nice strawman. You lose the argument though right?
- orf 10y ago
  > A number between 1 and 10 on Tuesday is only slightly different. You can say it is not arbitrary, whatever. It's not arbitrary, because the constraints at least in Postgres are themselves constrained to validating a single row in a single table. Your app code can be truly arbitrary, you could trigger a device that posts a carrier pigeon to someone many miles away and waits for it to return with a result. That's arbitrary. > Just in case you forgot the original claim, it was that if you use a SQL database, the constraints are in your database, but if you use mongo, the constraints are in your code. Sorry, that's not what I was claiming. I was stating, correctly, that constraints relating to the data belong in the database. Constraints belonging to the business logic that powers your app belong in your app. You can be 100% sure that a constraint in your database will be respected, whereas the same can't be said of your apps code. If you are given a specification that says "no username can be longer than 12 characters", that's what you add to your database constraints. A specification that says "No emails from temporary email providers are allowed" belong in your app code. Clear separation of concerns, that mongodb has no clue about. 'Just validate everything in your code, and if you get junk data in your database then I fucking hope your code can handle it'. Please. > Therefore, saying that it is a great win that a SQL database can do some basic constraints checking It can do pretty complex constraints. On the data. The more complex, completely arbitrary constraints belong in your app code. > is a ridiculous argument because it hardly contributes any benefit due to the fact that even more complex constraints are in the code. What. That makes no sense. So having 100% certainty that no column value in your database will violate any of the constraints you place on it 'hardly contributes any benefits' because... you have other, unrelated, business constraints in your app? What logic is this?

by orf 10y ago

1879325272 10y ago

This is just a semantics argument which is boring. A number between 1 and 10 on Tuesday is only slightly different. You can say it is not arbitrary, whatever. You have just proved my point. Just in case you forgot the original claim, it was that if you use a SQL database, the constraints are in your database, but if you use mongo, the constraints are in your code. I refuted this by saying that the constraints are also in the code in a SQL database. You have proven the point even further by highlighting that they are even more complex than the constraints in the database. Therefore, saying that it is a great win that a SQL database can do some basic constraints checking is a ridiculous argument because it hardly contributes any benefit due to the fact that even more complex constraints are in the code. So you have not actually contributed anything and I never said you should throw out SQL just because it can't model every constraint. Nice strawman. You lose the argument though right?

orf 10y ago
> A number between 1 and 10 on Tuesday is only slightly different. You can say it is not arbitrary, whatever. It's not arbitrary, because the constraints at least in Postgres are themselves constrained to validating a single row in a single table. Your app code can be truly arbitrary, you could trigger a device that posts a carrier pigeon to someone many miles away and waits for it to return with a result. That's arbitrary. > Just in case you forgot the original claim, it was that if you use a SQL database, the constraints are in your database, but if you use mongo, the constraints are in your code. Sorry, that's not what I was claiming. I was stating, correctly, that constraints relating to the data belong in the database. Constraints belonging to the business logic that powers your app belong in your app. You can be 100% sure that a constraint in your database will be respected, whereas the same can't be said of your apps code. If you are given a specification that says "no username can be longer than 12 characters", that's what you add to your database constraints. A specification that says "No emails from temporary email providers are allowed" belong in your app code. Clear separation of concerns, that mongodb has no clue about. 'Just validate everything in your code, and if you get junk data in your database then I fucking hope your code can handle it'. Please. > Therefore, saying that it is a great win that a SQL database can do some basic constraints checking It can do pretty complex constraints. On the data. The more complex, completely arbitrary constraints belong in your app code. > is a ridiculous argument because it hardly contributes any benefit due to the fact that even more complex constraints are in the code. What. That makes no sense. So having 100% certainty that no column value in your database will violate any of the constraints you place on it 'hardly contributes any benefits' because... you have other, unrelated, business constraints in your app? What logic is this?