[adrusi]

You usually want to know when you're hitting the database. "Hit the database if the value isn't cached" is useful behavior, but should probably be telegraphed a bit more precisely than just the word "size".

[mosselman]

“size” is fine. The person you are responding to is trying to say that complaining about multiple options is a bit strange as you can just use one option. Why is it an issue that other options exist? Who cares. There are synonyms for English words as well, is that an issue as well?

[tinus_hn]

They are not synonyms, they mean slightly different things. And that is the problem.

Because for small datasets the difference doesn’t matter this results in beginner programmers choosing randomly, which 2/3 of time is the wrong choice.

[mosselman]

So if 'length' was the only option and I'd have to do ActiveRecord::Base.connection.execute('SELECT count(*) FROM users').values.first or something it would all be fine?

[strken]

Other ORMs separate building the query from executing the query, which is less ergonomic but more explicit. Drawing on Rust, https://diesel.rs/ shows how this approach would work:

    users.select(count_star()).first(&connection)

which is really just a cleaned-up version of your suggestion.

Of course, you could imagine an ActiveRecord-like API to make this nicer:

    User.first{|t| t.count}
    User.first{|t| t.count}.execute!
    User.execute{|t| t.count}.values.first
    # ...etc.

but the underlying problem is that building the query and executing the query are two discrete steps, Rails streamlines them instead of making the separation obvious, and when a system hides complexity it becomes harder to know what it's really doing.

[adrusi]

"size" is not fine. If I'm conditionally hitting the database, I want that to be as explicit as possible.