> Bad news, :(
>
> I have to use Turkish collate...

Maybe not always?
In my area we've got similar issues with Collate=German.
What I do is still using Collate=Machine as default.
And locale collate only for things like an Index On Lastname etc.,
IOW, only those (rare) expressions where a locale order is actually required.
In my opinion, "machine" is preferable for an Index On phone, for example, and also especially for techno indices like an integer primary key, etc.


hth
-Stefan