diff --git a/spec/benchmark-cars.cr b/spec/benchmark-cars.cr
new file mode 100644
index 0000000..bb0eda3
--- /dev/null
+++ b/spec/benchmark-cars.cr
@@ -0,0 +1,141 @@
+require "benchmark"
+require "./benchmark-utilities.cr"
+
+require "../src/dodb.cr"
+require "./test-data.cr"
+
+class DODBCachedCars < DODB::CachedDataBase(Car)
+	property storage_dir : String
+	def initialize(storage_ext = "", remove_previous_data = true)
+		@storage_dir = "test-storage-cars-cached#{storage_ext}"
+
+		if remove_previous_data
+			::FileUtils.rm_rf storage_dir
+		end
+
+		super storage_dir
+	end
+
+	def rm_storage_dir
+		::FileUtils.rm_rf @storage_dir
+	end
+end
+
+class DODBUnCachedCars < DODB::DataBase(Car)
+	property storage_dir : String
+	def initialize(storage_ext = "", remove_previous_data = true)
+		@storage_dir = "test-storage-cars-uncached#{storage_ext}"
+
+		if remove_previous_data
+			::FileUtils.rm_rf storage_dir
+		end
+
+		super storage_dir
+	end
+
+	def rm_storage_dir
+		::FileUtils.rm_rf @storage_dir
+	end
+end
+
+def init_indexes(storage : DODB::Storage)
+	n = storage.new_index "name", &.name
+	c = storage.new_partition "color", &.color
+	k = storage.new_tags "keyword", &.keywords
+	return n, c, k
+end
+
+def add_cars(storage : DODB::Storage, nb_iterations : Int32)
+	i = 0
+	car1 = Car.new "Corvet", "red", [ "shiny", "impressive", "fast", "elegant" ]
+	car2 = Car.new "Bullet-GT", "blue", [ "shiny", "fast", "expensive" ]
+	car3 = Car.new "Deudeuche", "beige", [ "curvy", "sublime" ]
+	car4 = Car.new "Ford-5", "red", [ "unknown" ]
+	car5 = Car.new "C-MAX", "gray", [ "spacious", "affordable" ]
+
+	while i < nb_iterations
+		car1.name = "Corvet-#{i}"
+		car2.name = "Bullet-GT-#{i}"
+		car3.name = "Deudeuche-#{i}"
+		car4.name = "Ford-5-#{i}"
+		car5.name = "C-MAX-#{i}"
+
+		storage << car1
+		storage << car2
+		storage << car3
+		storage << car4
+		storage << car5
+		i += 1
+		STDOUT.write "\radding value #{i}".to_slice
+	end
+	puts ""
+end
+
+cars_cached = DODBCachedCars.new
+cars_uncached = DODBUnCachedCars.new
+
+cached_searchby_name,   cached_searchby_color,   cached_searchby_keywords   = init_indexes cars_cached
+uncached_searchby_name, uncached_searchby_color, uncached_searchby_keywords = init_indexes cars_uncached
+
+add_cars cars_cached,   1_000
+add_cars cars_uncached, 1_000
+
+# Searching for data with an index.
+Benchmark.ips do |x|
+	x.report("(cars db) searching a data with an index (with a cache)") do
+		corvet = cached_searchby_name.get "Corvet-500"
+	end
+
+	x.report("(cars db) searching a data with an index (without a cache)") do
+		corvet = uncached_searchby_name.get "Corvet-500"
+	end
+end
+
+# Searching for data with a partition.
+Benchmark.ips do |x|
+	x.report("(cars db) searching a data with a partition (with a cache)") do
+		red_cars = cached_searchby_color.get "red"
+	end
+
+	x.report("(cars db) searching a data with a partition (without a cache)") do
+		red_cars = cached_searchby_color.get "red"
+	end
+end
+
+# Searching for data with a tag.
+Benchmark.ips do |x|
+	x.report("(cars db) searching a data with a tag (with a cache)") do
+		red_cars = cached_searchby_keywords.get "spacious"
+	end
+
+	x.report("(cars db) searching a data with a tag (without a cache)") do
+		red_cars = cached_searchby_keywords.get "spacious"
+	end
+end
+
+cars_cached.rm_storage_dir
+cars_uncached.rm_storage_dir
+
+cars_cached = DODBCachedCars.new
+cars_uncached = DODBUnCachedCars.new
+
+#init_indexes cars_cached
+#init_indexes cars_uncached
+cached_searchby_name,   cached_searchby_color,   cached_searchby_keywords   = init_indexes cars_cached
+uncached_searchby_name, uncached_searchby_color, uncached_searchby_keywords = init_indexes cars_uncached
+
+add_cars cars_cached,   1_000
+add_cars cars_uncached, 1_000
+
+nb_run = 1000
+
+perform_benchmark_average_verbose "(cached) search db with an index", nb_run, do
+	cached_searchby_name.get "Corvet-500"
+end
+
+perform_benchmark_average_verbose "(uncached) search db with an index", nb_run, do
+	uncached_searchby_name.get "Corvet-500"
+end
+
+cars_cached.rm_storage_dir
+cars_uncached.rm_storage_dir
diff --git a/spec/benchmark-utilities.cr b/spec/benchmark-utilities.cr
new file mode 100644
index 0000000..5627560
--- /dev/null
+++ b/spec/benchmark-utilities.cr
@@ -0,0 +1,32 @@
+def perform_something(&block)
+	start = Time.monotonic
+	yield
+	Time.monotonic - start
+end
+
+def perform_benchmark_average(ntimes : Int32, &block)
+	i = 1
+	sum = Time::Span.zero
+	while i <= ntimes
+		elapsed_time = perform_something &block
+		sum += elapsed_time
+		i += 1
+	end
+
+	sum / ntimes
+end
+
+def perform_benchmark_average_verbose(title : String, ntimes : Int32, &block)
+	i = 1
+	sum = Time::Span.zero
+	puts "Execute '#{title}' × #{ntimes}"
+	while i <= ntimes
+		elapsed_time = perform_something &block
+		sum += elapsed_time
+		STDOUT.write "\relapsed_time: #{elapsed_time}, average: #{sum/i}".to_slice
+
+		i += 1
+	end
+	puts ""
+	puts "Average: #{sum/ntimes}"
+end
diff --git a/spec/test-data.cr b/spec/test-data.cr
index 2df42ed..09be46d 100644
--- a/spec/test-data.cr
+++ b/spec/test-data.cr
@@ -85,3 +85,22 @@ class PrimitiveShip
 		@@asakaze
 	]
 end
+
+class Car
+	include JSON::Serializable
+
+	property name     : String        # unique to each instance (1-1 relations)
+	property color    : String        # a simple attribute (1-n relations)
+	property keywords : Array(String) # tags about a car, example: "shiny" (n-n relations)
+
+	def initialize(@name, @color, @keywords)
+	end
+	class_getter cars = [
+		Car.new("Corvet",    "red",    [ "shiny", "impressive", "fast", "elegant" ]),
+		Car.new("SUV",       "red",    [ "solid", "impressive" ]),
+		Car.new("Mustang",   "red",    [ "shiny", "impressive", "elegant" ]),
+		Car.new("Bullet-GT", "red",    [ "shiny", "impressive", "fast", "elegant" ]),
+		Car.new("GTI",       "blue",   [ "average" ]),
+		Car.new("Deudeuch",  "violet", [ "dirty", "slow", "only French will understand" ])
+	]
+end