lib/shiba/index_stats.rb in shiba-0.2.3 vs lib/shiba/index_stats.rb in shiba-0.3.0

@@ -95,13 +95,12 @@
       def encode_with(coder)
         coder.map = {'column' => @column}
 
         count = table_count
         count = 1 if count == 0
-        ratio_per_item = self.rows_per / count.to_f rescue debugger
+        ratio_per_item = self.rows_per / count.to_f
 
-
         if count <= 10
           ratio_threshold = 1_000_0000 # always show a number
         elsif count <= 1000
           ratio_threshold = 0.1
         elsif count <= 1_000_000
@@ -156,14 +155,19 @@
     def estimate_key(table_name, key, parts)
       index = fetch_index(table_name, key)
 
       return nil unless index
 
-      index_part = index.columns.detect do |p|
-        p.column == parts.last
+      index_part = nil
+      index.columns.each do |c|
+        break unless parts.include?(c.column)
+        index_part = c
       end
 
-      return nil unless index_part
+      # postgres can claim to use the right hand side of an index
+      # in a bitmap scan, which seems to be a side-effect of forcing
+      # seq-scan off.  In these cases we'll say it's a full scan.
+      return table_count(table_name) unless index_part
 
       index_part.rows_per
     end
 
     def convert_rows_per_to_output!