Polyphase Merge

I'm trying to refine the sorting module of tuplesort.c

During run creations I use two heaps instead of just one (yeah, it's still me... the one of the two heaps still trying to get some answer/help from -hackers)

Those two runs are built in a way such that if we would concatenate one of them to the other one red upside down, they will still form a run (recall that following Knuth, a "run" is a sorted sequence of data). There are a lot of possibility that with that refinement "logical runs" could be longer than ordinary runs built by the ordinary replacement selection. Remark we build runs: logical runs it's just a concept used to understand why we build runs that way.

ISSUES
a) how to distribute logical runs (that is both of its physical runs) into tapes?
b) one of the 2 physical runs of the logical run is to be red upside down while merging: how to efficiently do it?

Well, that's all for now.

Hope you can please give to me few seconds of you precious time. That would allow me to go on developing my refinement. Or at least tell me don't bother till the day next PostgreSQL release is out (when will it be released?) or don't bother anymore since nobody will ever answer to me.

Thanks for your attention.
Manolo.