diff --git a/spec/db-cars.cr b/spec/db-cars.cr
index 4f81532..d767bb5 100644
--- a/spec/db-cars.cr
+++ b/spec/db-cars.cr
@@ -31,31 +31,31 @@ class Car
 end
 
 def ram_indexes(storage : DODB::Storage)
-	n = storage.new_nilable_RAM_index "name", &.name
-	c = storage.new_nilable_RAM_partition "color", &.color
-	k = storage.new_nilable_RAM_tags "keyword", &.keywords
+	n = storage.new_RAM_index "name", &.name
+	c = storage.new_RAM_partition "color", &.color
+	k = storage.new_RAM_tags "keyword", &.keywords
 	return n, c, k
 end
 
 def cached_indexes(storage : DODB::Storage)
-	n = storage.new_nilable_index "name", &.name
-	c = storage.new_nilable_partition "color", &.color
-	k = storage.new_nilable_tags "keyword", &.keywords
+	n = storage.new_index "name", &.name
+	c = storage.new_partition "color", &.color
+	k = storage.new_tags "keyword", &.keywords
 	return n, c, k
 end
 
 def uncached_indexes(storage : DODB::Storage)
-	n = storage.new_nilable_uncached_index "name", &.name
-	c = storage.new_nilable_uncached_partition "color", &.color
-	k = storage.new_nilable_uncached_tags "keyword", &.keywords
+	n = storage.new_uncached_index "name", &.name
+	c = storage.new_uncached_partition "color", &.color
+	k = storage.new_uncached_tags "keyword", &.keywords
 	return n, c, k
 end
 
 # `max_indexes` limits the number of indexes (partitions and tags).
-# Once the last index (db last_index/5) is above this value, the following
+# Once the last index (db last_key/5) is above this value, the following
 # cars won't be tagged nor partitionned.
 def add_cars(storage : DODB::Storage, nb_iterations : Int32, max_indexes = 5000)
-	last_index = ((storage.last_index + 1) / 5).to_i
+	last_key = ((storage.last_key + 1) / 5).to_i
 	i = 0
 	car1 = Car.new "Corvet", "red", [ "shiny", "impressive", "fast", "elegant" ]
 	car2 = Car.new "Bullet-GT", "blue", [ "shiny", "fast", "expensive" ]
@@ -64,15 +64,15 @@ def add_cars(storage : DODB::Storage, nb_iterations : Int32, max_indexes = 5000)
 	car5 = Car.new "C-MAX", "gray", [ "spacious", "affordable" ]
 
 	while i < nb_iterations
-		car1.name = "Corvet-#{last_index}"
-		car2.name = "Bullet-GT-#{last_index}"
-		car3.name = "Deudeuche-#{last_index}"
-		car4.name = "Ford-5-#{last_index}"
-		car5.name = "C-MAX-#{last_index}"
+		car1.name = "Corvet-#{last_key}"
+		car2.name = "Bullet-GT-#{last_key}"
+		car3.name = "Deudeuche-#{last_key}"
+		car4.name = "Ford-5-#{last_key}"
+		car5.name = "C-MAX-#{last_key}"
 
-		last_index += 1
+		last_key += 1
 
-		if last_index > max_indexes
+		if last_key > max_indexes
 			car1.color = DODB.no_index
 			car2.color = DODB.no_index
 			car3.color = DODB.no_index
@@ -86,11 +86,11 @@ def add_cars(storage : DODB::Storage, nb_iterations : Int32, max_indexes = 5000)
 			car5.keywords = DODB.no_index
 		end
 
-		storage << car1.clone
-		storage << car2.clone
-		storage << car3.clone
-		storage << car4.clone
-		storage << car5.clone
+		storage.unsafe_add car1.clone
+		storage.unsafe_add car2.clone
+		storage.unsafe_add car3.clone
+		storage.unsafe_add car4.clone
+		storage.unsafe_add car5.clone
 		i += 1
 		#STDOUT.write "\radding value #{i}".to_slice
 	end