[mattashii]

> Postgres is “just” a SQL engine running on top of a key-value heap and trees pointing into it.

I wouldn't call heaps a key-value data structure; even if you could argue that the location of your data is an implicit key. And the trees are strictly optional - you could build your database with only hash and brin indexes.

[jakewins]

Yeah agree, I had the same thought after I wrote that comment “wait dumbass, you don’t get to pick the key in the heap, it’s not the same”.

But still, you get what I’m getting at: in the end, the relational dbs, internally, build on top of abstractions that are things like trees, key-value structures, heaps, logs etc.