I agree with this, but I'd also add that if your ORM is doing a lot beyond the capabilities of your database, it's an indicator of a hacky design in your application. If there's a large object/relational impedance mismatch, then either the objects or the relational DB are a poor fit for the problem you're trying to solve, and an ORM can't really fix that.

If your ORM is just providing a mapping between select/map, where/filter, join/zip, etc., you have a fairly list-of-records-ish functional application and your objects are only nominally objects. The ORM is only providing an interface that lines your types up (and the benefits of that are not to be underestimated--it allows, for example, running your app on different database engines).

But if your ORM is doing more than that, it's usually because your objects have a lot of complicated graph vertices that are poorly represented by tables. ORMs can reduce the difficulty of this object/relational impedance mismatch, but ultimately they can't provide a general solution for it, because the data structure they're sitting on top of doesn't have the capability. ORMs can make your code simpler, but they can't make SQL performant on, for example, directed graph or deep tree structures. Ultimately, they only mitigate the object/relational impedance mismatch, they don't solve it.

Again, as I parenthesized earlier, the benefits of ORMs still aren't to be underestimated. But I think a lot of those benefits can be realized with a simple wrapper around SQL (i.e. LINQ). Beyond that, all ORMs provide is a little fudge factor which lets you get away with some things that SQL doesn't support well, but ultimately ORMs aren't a general solution to those kinds of problems.

> If there's a large object/relational impedance mismatch, then either the objects or the relational DB are a poor fit for the problem you're trying to solve.

Why? You're just making that assumption but the fact is that relational databases and the normalized storage of data is completely different from the way OO languages deal with rich nested objects. And there's nothing wrong with that mismatch because there will always be a mismatch. It's just 2 different paradigms of handling data. All an ORM is doing is giving you a tool to make that translation easier, if you want it. If you really can't have the mismatch then there are document-stores available but in most cases, the O/R mapping is just not a big deal.

> But I think a lot of those benefits can be realized with a simple wrapper around SQL (i.e. LINQ).

That's basically still an ORM. Again why the assumption that just because you have an ORM that anything and everything must be piped through it? The modern ones let you use ORM methods in your code and chain them with custom raw SQL too. ORM usage is on a spectrum, it's not binary and there's definitely no "right" way to use them.

I suspect you're viewing my previous comment as a criticism of ORMs. I tried to make it clear that it was not a criticism of ORMs. It's more a criticism of people who try use ORMs to whitewash a bad design or get around a problem that relational databases can't solve. Relational databases lend themselves to a very specific way of structuring data, and if you don't structure your data that way or your data can't be structured that way, an ORM won't fix it. That doesn't mean ORMs are bad, it means that ORMs have to be used as intended and often people don't use them as intended. That's not the fault of the ORM any more than it's the fault of a screwdriver when it's used to saw wood.

Nobody uses a screwdriver to saw wood. But they're great as replacement paint stirrers and hole punches.

That's my bad ORM misuse analogy.

As a maintenance programmer, it really fries my bacon when I find all the screwdrivers next to the old paint cans.

I think when people talk about using an ORM or not they're mostly talking about using a LINQ-like wrapper or not. There's maybe a conversation to be had about some kind of fancier features on top of your ORM and whether they're worth it, but I don't think those kind of features are what people usually mean when they talk about ORMs (whether they're technically what the acronym "should" mean or not).

> interfacing through the object/relational impedance mismatch

Do we really need the regular code with it's traditional OOP and fat application server to convert result set to JSON and spit it out - that most of the time is all that code is doing actually? I suppose these typical tasks might be pretty much covered not only by PostgREST [1], but with just a sweet combination of two PostgreSQL functions - array_to_json() and array_agg().

[1] http://postgrest.com/

> you're not really using an ORM for much at all.

The ORM can do transient fault recovery (including other cloud patterns) as well as modernise the interface (Micro-ORMs in general).