I suspect this is an XY problem, can you elaborate better what's the original task to be solved? It's unusual to use those sort expressions in Solr.
Maybe we can solve it differently, at indexing time or maybe using some ranking models (like a linear one on learning to rank, but using not learned multipliers). Cheers On Wed, 1 Nov 2023, 09:40 Ing. Andrea Vettori, <a.vett...@b2bires.com> wrote: > Hello, > I’m looking for the most efficient way to specify sorting on expressions > when they’re complex. > For example, suppose that there are fields a1, a2, ….., an and I need to > sort for the sum of them. In this case it’s “easy” using > sum(def(a1,0),def(a2,0),…,def(an,0)) as expression. > Now suppose there are also fields b1, b2, …. bm, and I want to sort by the > ratio between the sum of all a(s) and the sum of b(s) i.e. > div(sum(def(a1,0),def(a2,0),…,def(an,0)), > sum(def(b1,0),def(b2,0),…,def(bm,0))). > This expression works but it can cause a division by zero. So, supposing > we want zero as the result when the sum of all b(s) is zero, the sorting > expression becomes > > if ( sum(def(b1,0),def(b2,0),…,def(bm,0)), > div(sum(def(a1,0),def(a2,0),…,def(an,0)), > sum(def(b1,0),def(b2,0),…,def(bm,0))), 0) > > is this efficient, i.e. does solr recognize that there are two > subexpression that are the same and calculate them just once ? > Does a better way to do this exist ? > > A similar question can be asked for json stats. > > Thanks! > — > Ing. Andrea Vettori > Sistemi Informativi > B2BIres s.r.l. > >
