I noticed that we're calling _bt_nonkey_truncate() needlessly when a
minimum key is needed at the leftmost page on each level of the tree.
This was always a special case, and I think that it should remain as
one. Attached patch avoids unneeded truncations, while preserving the
generic BTreeTupleGetNAtts() assertions.
This isn't a correctness issue, and the extra overhead of unneeded
truncation should be negligible, but what we have now seems confusing
to me.
--
Peter Geoghegan