add segment to table comparison endpoint

src/metabase/api/fingerprint.clj

@@ -149,4 +149,15 @@
               {:max-cost (max-cost max_query_cost max_computation_cost)})
        fingerprinters/prettify))
 
+(api/defendpoint GET "/compare/segment/:sid/table/:tid"
+  "Compare `Segment` with `Table`."
+  [sid tid max_query_cost max_computation_cost]
+  {max_query_cost       MaxQueryCost
+   max_computation_cost MaxComputationCost}
+  (fingerprinters/prettify
+   (fingerprinting/compare-fingerprints
+    {:max-cost (max-cost max_query_cost max_computation_cost)}
+    (api/read-check Segment sid)
+    (api/read-check Table tid))))
+
 (api/define-routes)

src/metabase/fingerprinting/core.clj

@@ -124,7 +124,6 @@
 (defn compare-fingerprints
   "Compare fingerprints of two models."
   [opts a b]
-  (assert (= (keys a) (keys b)))
   (let [[a b] (map (partial fingerprint opts) [a b])]
     {:constituents [a b]
      :comparison   (into {}

src/metabase/fingerprinting/fingerprinters.clj

@@ -131,6 +131,7 @@
           :has-nils?            (pos? nil-count)
           :0<=x<=1?             (<= 0 min max 1)
           :-1<=x<=1?            (<= -1 min max 1)
+          :cv                   (safe-divide mean sd)
           :span-vs-sd           (safe-divide span sd)
           :mean-median-spread   (safe-divide span (- mean median))
           :min-vs-max           (safe-divide min max)

src/metabase/fingerprinting/histogram.clj

@@ -21,7 +21,7 @@
 
 (def ^{:arglists '([^Histogram histogram])} categorical?
   "Returns true if given histogram holds categorical values."
-  (comp some? impl/target-type))
+  (comp (complement #{:none}) impl/target-type))
 
 (defn pdf
   "Probability density function of given histogram.