PostgreSQL requires all tables with FKs to be truncates in the same

command, or have the CASCADE keyword appended.

lib/database_cleaner/sequel/truncation.rb

@@ -8,8 +8,21 @@ class Truncation
       include ::DatabaseCleaner::Generic::Truncation
 
       def clean
-        each_table do |db, table|
-          db[table].truncate
+        case db_type= db.url.sub(/:.+/,'').to_sym
+        when :postgres
+          # PostgreSQL requires all tables with FKs to be truncates in the same command, or have the CASCADE keyword
+          # appended. Bulk truncation without CASCADE is:
+          # * Safer. Tables outside of tables_to_truncate won't be affected.
+          # * Faster. Less roundtrips to the db.
+          unless (tables= tables_to_truncate(db)).empty?
+            all_tables= tables.map{|t| %["#{t}"]}.join ','
+            db.run "TRUNCATE TABLE #{all_tables};"
+          end
+        else
+          # Truncate each table normally
+          each_table do |db, table|
+            db[table].truncate
+          end
         end
       end