Hi Tom,
The patches look entirely reasonable to me.
The second one needs to be rebased.
I like the idea of stubbing matchjoinsel for now,
as well as being careful with operators that may correlate with sort
orderings.
The only little thing I can think of is hardcoding it as 2 * DEFAULT_EQ_SEL.
While I don't have any arguments against the value itself I think it
should be configurable independently.
Sadly DEFAULT_MATCH_SEL name is already taken for text patterns.
Not sure if it's a reason to rename all the stuff.
Best, Alex