If all you need is the next page and there is only ever one next page, then deal with it that way.
I did have the words "If" and "might" in my post y'know ;-) If all you need is the next page then it's obviously overkill. If you're doing more complex stuff a more generic solution is worth looking at.
Now, you could build the queries using some module (???), but the queries are very very very slow and very very very difficult to get right.
Erm. No they're not. The queries are damn quick. You have a representation that leverages the things that RDBMS are good at. .
As for difficult to get right - not particularly in my opinion. Takes a little time to get your head around the representation - but the operations to access nodes and subtrees are pretty simple. Insertion is the only vaguely complicated operation.
Hmm... I feel a meditation coming on...