I wrote:
... to control the precise SQL that is generated. In practice, you almost always have to do some tweaking that is at least DB-dependent, and often application dependent.
Peter Verswyvelen wrote:
Can't the same be said regarding SQL itself? It sometimes needs tweaking. That's the problem with any high level abstraction no?
Certainly. In an ideal world, you could just write your queries in straightforward SQL and the DB would figure out what to do. But in real life, that is not how it works. So that complexity then gets passed up to the Haskell interface layers. Again, in an ideal world you would like to imagine that a high-level interface like haskelldb would be smart enough to compile any relational algebraic expression into SQL that will do the Right Thing for the given backend. But that would be very difficult. For example - there may be things you need to tweak that are both application-dependent and DB dependent. So to be usable in a serious DB project, there would have to be some kind of hooks that would allow you to tweak the SQL. After doing that - what have we gained by taking the high-level approach to begin with? I'm not sure. I would like to hear about people's thoughts and experiences on this. -Yitz