diff --git a/backend/src/app/db.clj b/backend/src/app/db.clj
index 704c7224a..c874fb9cc 100644
--- a/backend/src/app/db.clj
+++ b/backend/src/app/db.clj
@@ -233,14 +233,14 @@
   ([ds table params opts]
    (exec-one! ds
               (sql/insert table params opts)
-              (assoc opts :return-keys true))))
+              (merge {:return-keys true} opts))))
 
 (defn insert-multi!
   ([ds table cols rows] (insert-multi! ds table cols rows nil))
   ([ds table cols rows opts]
    (exec! ds
           (sql/insert-multi table cols rows opts)
-          (assoc opts :return-keys true))))
+          (merge {:return-keys true} opts))))
 
 (defn update!
   ([ds table params where] (update! ds table params where nil))
diff --git a/backend/src/app/main.clj b/backend/src/app/main.clj
index 4d785de3d..6a88a10c4 100644
--- a/backend/src/app/main.clj
+++ b/backend/src/app/main.clj
@@ -189,7 +189,7 @@
     :pool       (ig/ref :app.db/pool)
     :entries
     [{:cron #app/cron "0 0 0 * * ?" ;; daily
-      :task :file-media-gc}
+      :task :file-gc}
 
      {:cron #app/cron "0 0 * * * ?"  ;; hourly
       :task :file-xlog-gc}
@@ -231,7 +231,7 @@
     :tasks
     {:sendmail           (ig/ref :app.emails/sendmail-handler)
      :objects-gc         (ig/ref :app.tasks.objects-gc/handler)
-     :file-media-gc      (ig/ref :app.tasks.file-media-gc/handler)
+     :file-gc            (ig/ref :app.tasks.file-gc/handler)
      :file-xlog-gc       (ig/ref :app.tasks.file-xlog-gc/handler)
      :storage-deleted-gc (ig/ref :app.storage/gc-deleted-task)
      :storage-touched-gc (ig/ref :app.storage/gc-touched-task)
@@ -262,7 +262,7 @@
     :storage (ig/ref :app.storage/storage)
     :max-age cf/deletion-delay}
 
-   :app.tasks.file-media-gc/handler
+   :app.tasks.file-gc/handler
    {:pool    (ig/ref :app.db/pool)
     :max-age cf/deletion-delay}
 
diff --git a/backend/src/app/rpc/mutations/files.clj b/backend/src/app/rpc/mutations/files.clj
index cb6bd5aa3..c3014bfc8 100644
--- a/backend/src/app/rpc/mutations/files.clj
+++ b/backend/src/app/rpc/mutations/files.clj
@@ -58,8 +58,9 @@
          (db/insert! conn :file-profile-rel))))
 
 (defn create-file
-  [conn {:keys [id name project-id is-shared data deleted-at]
+  [conn {:keys [id name project-id is-shared data deleted-at revn]
          :or {is-shared false
+              revn 0
               deleted-at nil}
          :as params}]
   (let [id   (or id (:id data) (uuid/next))
@@ -68,6 +69,7 @@
                          {:id id
                           :project-id project-id
                           :name name
+                          :revn revn
                           :is-shared is-shared
                           :data (blob/encode data)
                           :deleted-at deleted-at})]
@@ -500,13 +502,13 @@
 ;; --- Mutation: Upsert file thumbnail
 
 (def sql:upsert-file-thumbnail
-  "insert into file_thumbnail(file_id, revn, data, props)
-   values (?, ?, ?, ?)
+  "insert into file_thumbnail (file_id, revn, data, props)
+   values (?, ?, ?, ?::jsonb)
        on conflict(file_id, revn) do
-          update set data = ?, updated_at=now();")
+          update set data = ?, props=?, updated_at=now();")
 
-(s/def ::revn  ::us/integer)
-(s/def ::props (s/map-of ::us/keyword any?))
+(s/def ::revn ::us/integer)
+(s/def ::props map?)
 (s/def ::upsert-file-thumbnail
   (s/keys :req-un [::profile-id ::file-id ::revn ::data ::props]))
 
@@ -516,5 +518,5 @@
     (files/check-edition-permissions! conn profile-id file-id)
     (let [props (db/tjson (or props {}))]
       (db/exec-one! conn [sql:upsert-file-thumbnail
-                          file-id revn data props data])
+                          file-id revn data props data props])
       nil)))
diff --git a/backend/src/app/rpc/queries/files.clj b/backend/src/app/rpc/queries/files.clj
index 935b41c8e..db6dfc45e 100644
--- a/backend/src/app/rpc/queries/files.clj
+++ b/backend/src/app/rpc/queries/files.clj
@@ -440,7 +440,7 @@
   (let [params (cond-> {:file-id file-id}
                  frame-id (assoc :frame-id frame-id))
         rows   (db/query pool :file-frame-thumbnail params)]
-    (d/group-by :frame-id :data rows)))
+    (d/index-by :frame-id :data rows)))
 
 ;; --- QUERY: get file thumbnail
 
@@ -465,10 +465,11 @@
       (ex/raise :type :not-found
                 :code :file-thumbnail-not-found))
 
-    (with-meta {:data (:data row)
-                :props (some-> (:props row) db/decode-transit-pgobject)
-                :revn (:revn row)
-                :file-id (:file-id row)}
+    (with-meta
+      {:data (:data row)
+       :props (some-> (:props row) db/decode-transit-pgobject)
+       :revn (:revn row)
+       :file-id (:file-id row)}
       {:transform-response (rpch/http-cache {:max-age (* 1000 60 60)})})))
 
 ;; --- Helpers
diff --git a/backend/src/app/tasks/file_gc.clj b/backend/src/app/tasks/file_gc.clj
new file mode 100644
index 000000000..b8669d96b
--- /dev/null
+++ b/backend/src/app/tasks/file_gc.clj
@@ -0,0 +1,164 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) UXBOX Labs SL
+
+(ns app.tasks.file-gc
+  "A maintenance task that is responsible of: purge unused file media,
+  clean unused frame thumbnails and remove old file thumbnails.  The
+  file is eligible to be garbage collected after some period of
+  inactivity (the default threshold is 72h)."
+  (:require
+   [app.common.data :as d]
+   [app.common.logging :as l]
+   [app.common.pages.helpers :as cph]
+   [app.common.pages.migrations :as pmg]
+   [app.db :as db]
+   [app.util.blob :as blob]
+   [app.util.time :as dt]
+   [clojure.spec.alpha :as s]
+   [integrant.core :as ig]))
+
+(declare ^:private retrieve-candidates)
+(declare ^:private process-file)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; HANDLER
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(s/def ::max-age ::dt/duration)
+
+(defmethod ig/pre-init-spec ::handler [_]
+  (s/keys :req-un [::db/pool ::max-age]))
+
+(defmethod ig/init-key ::handler
+  [_ {:keys [pool] :as cfg}]
+  (fn [_]
+    (db/with-atomic [conn pool]
+      (let [cfg (assoc cfg :conn conn)]
+        (loop [total 0
+               files (retrieve-candidates cfg)]
+          (if-let [file (first files)]
+            (do
+              (process-file cfg file)
+              (recur (inc total)
+                     (rest files)))
+            (do
+              (l/debug :msg "finished processing files" :processed total)
+              {:processed total})))))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; IMPL
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+
+(def ^:private
+  sql:retrieve-candidates-chunk
+  "select f.id,
+          f.data,
+          f.revn,
+          f.modified_at
+     from file as f
+    where f.has_media_trimmed is false
+      and f.modified_at < now() - ?::interval
+      and f.modified_at < ?
+    order by f.modified_at desc
+    limit 1
+    for update skip locked")
+
+(defn- retrieve-candidates
+  [{:keys [conn max-age] :as cfg}]
+  (let [interval (db/interval max-age)
+
+        get-chunk
+        (fn [cursor]
+          (let [rows (db/exec! conn [sql:retrieve-candidates-chunk interval cursor])]
+            [(some->> rows peek :modified-at) (seq rows)]))]
+
+    (sequence cat (d/iteration get-chunk
+                               :vf second
+                               :kf first
+                               :initk (dt/now)))))
+
+(defn- collect-used-media
+  [data]
+  (let [xform (comp
+               (map :objects)
+               (mapcat vals)
+               (keep (fn [{:keys [type] :as obj}]
+                       (case type
+                         :path (get-in obj [:fill-image :id])
+                         :image (get-in obj [:metadata :id])
+                         nil))))
+        pages (concat
+               (vals (:pages-index data))
+               (vals (:components data)))]
+    (-> #{}
+        (into xform pages)
+        (into (keys (:media data))))))
+
+(defn- clean-file-media!
+  "Performs the garbage collection of file media objects."
+  [conn file-id data]
+  (let [used   (collect-used-media data)
+        unused (->> (db/query conn :file-media-object {:file-id file-id})
+                    (remove #(contains? used (:id %))))]
+
+    (doseq [mobj unused]
+      (l/debug :hint "delete file media object"
+               :id (:id mobj)
+               :media-id (:media-id mobj)
+               :thumbnail-id (:thumbnail-id mobj))
+
+      ;; NOTE: deleting the file-media-object in the database
+      ;; automatically marks as touched the referenced storage
+      ;; objects. The touch mechanism is needed because many files can
+      ;; point to the same storage objects and we can't just delete
+      ;; them.
+      (db/delete! conn :file-media-object {:id (:id mobj)}))))
+
+(defn- collect-frames
+  [data]
+  (let [xform (comp
+               (map :objects)
+               (mapcat vals)
+               (filter cph/frame-shape?)
+               (keep :id))
+        pages (concat
+               (vals (:pages-index data))
+               (vals (:components data)))]
+    (into #{} xform pages)))
+
+(defn- clean-file-frame-thumbnails!
+  [conn file-id data]
+  (let [sql (str "delete from file_frame_thumbnail "
+                 " where file_id=? and not (frame_id=ANY(?))")
+        ids (->> (collect-frames data)
+                 (db/create-array conn "uuid"))
+        res (db/exec-one! conn [sql file-id ids])]
+    (l/debug :hint "delete frame thumbnails" :total (:next.jdbc/update-count res))))
+
+(defn- clean-file-thumbnails!
+  [conn file-id revn]
+  (let [sql (str "delete from file_thumbnail "
+                 " where file_id=? and revn < ?")
+        res (db/exec-one! conn [sql file-id revn])]
+    (l/debug :hint "delete file thumbnails" :total (:next.jdbc/update-count res))))
+
+(defn- process-file
+  [{:keys [conn] :as cfg} {:keys [id data revn modified-at] :as file}]
+  (l/debug :hint "processing file" :id id :modified-at modified-at)
+
+  (let [data (-> (blob/decode data)
+                 (assoc :id id)
+                 (pmg/migrate-data))]
+
+    (clean-file-media! conn id data)
+    (clean-file-frame-thumbnails! conn id data)
+    (clean-file-thumbnails! conn id revn)
+
+    ;; Mark file as trimmed
+    (db/update! conn :file
+                  {:has-media-trimmed true}
+                  {:id id})
+    nil))
diff --git a/backend/src/app/tasks/file_media_gc.clj b/backend/src/app/tasks/file_media_gc.clj
deleted file mode 100644
index 40f55f53f..000000000
--- a/backend/src/app/tasks/file_media_gc.clj
+++ /dev/null
@@ -1,139 +0,0 @@
-;; This Source Code Form is subject to the terms of the Mozilla Public
-;; License, v. 2.0. If a copy of the MPL was not distributed with this
-;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
-;;
-;; Copyright (c) UXBOX Labs SL
-
-(ns app.tasks.file-media-gc
-  "A maintenance task that is responsible to purge the unused media
-  objects from files. A file is eligible to be garbage collected
-  after some period of inactivity (the default threshold is 72h)."
-  (:require
-   [app.common.logging :as l]
-   [app.common.pages.helpers :as cph]
-   [app.common.pages.migrations :as pmg]
-   [app.db :as db]
-   [app.util.blob :as blob]
-   [app.util.time :as dt]
-   [clojure.spec.alpha :as s]
-   [integrant.core :as ig]))
-
-(declare process-file)
-(declare retrieve-candidates)
-
-(s/def ::max-age ::dt/duration)
-
-(defmethod ig/pre-init-spec ::handler [_]
-  (s/keys :req-un [::db/pool ::max-age]))
-
-(defmethod ig/init-key ::handler
-  [_ {:keys [pool] :as cfg}]
-  (fn [_]
-    (db/with-atomic [conn pool]
-      (let [cfg (assoc cfg :conn conn)]
-        (loop [n 0]
-          (let [files (retrieve-candidates cfg)]
-            (if (seq files)
-              (do
-                (run! (partial process-file cfg) files)
-                (recur (+ n (count files))))
-              (do
-                (l/debug :msg "finished processing files" :processed n)
-                {:processed n}))))))))
-
-(def ^:private
-  sql:retrieve-candidates-chunk
-  "select f.id,
-          f.data,
-          extract(epoch from (now() - f.modified_at))::bigint as age
-     from file as f
-    where f.has_media_trimmed is false
-      and f.modified_at < now() - ?::interval
-    order by f.modified_at asc
-    limit 10
-    for update skip locked")
-
-
-(defn- retrieve-candidates
-  [{:keys [conn max-age] :as cfg}]
-  (let [interval (db/interval max-age)]
-    (->> (db/exec! conn [sql:retrieve-candidates-chunk interval])
-         (mapv (fn [{:keys [age] :as row}]
-                 (assoc row :age (dt/duration {:seconds age})))))))
-
-(def ^:private
-  collect-media-xf
-  (comp
-   (map :objects)
-   (mapcat vals)
-   (keep (fn [{:keys [type] :as obj}]
-           (case type
-             :path (get-in obj [:fill-image :id])
-             :image (get-in obj [:metadata :id])
-             nil)))))
-
-(defn- collect-used-media
-  [data]
-  (let [pages (concat
-               (vals (:pages-index data))
-               (vals (:components data)))]
-  (-> #{}
-      (into collect-media-xf pages)
-      (into (keys (:media data))))))
-
-(def ^:private
-  collect-frames-xf
-  (comp
-   (map :objects)
-   (mapcat vals)
-   (filter cph/frame-shape?)
-   (keep :id)))
-
-(defn- collect-frames
-  [data]
-  (let [pages (concat
-               (vals (:pages-index data))
-               (vals (:components data)))]
-    (into #{} collect-frames-xf pages)))
-
-(defn- process-file
-  [{:keys [conn] :as cfg} {:keys [id data age] :as file}]
-  (let [data (-> (blob/decode data)
-                 (assoc :id id)
-                 (pmg/migrate-data))]
-
-    (let [used   (collect-used-media data)
-          unused (->> (db/query conn :file-media-object {:file-id id})
-                      (remove #(contains? used (:id %))))]
-
-      (l/debug :hint "processing file"
-               :id id
-               :age age
-               :to-delete (count unused))
-
-      ;; Mark file as trimmed
-      (db/update! conn :file
-                  {:has-media-trimmed true}
-                  {:id id})
-
-      (doseq [mobj unused]
-        (l/debug :hint "deleting media object"
-                 :id (:id mobj)
-                 :media-id (:media-id mobj)
-                 :thumbnail-id (:thumbnail-id mobj))
-
-        ;; NOTE: deleting the file-media-object in the database
-        ;; automatically marks as touched the referenced storage
-        ;; objects. The touch mechanism is needed because many files can
-        ;; point to the same storage objects and we can't just delete
-        ;; them.
-        (db/delete! conn :file-media-object {:id (:id mobj)})))
-
-    (let [sql (str "delete from file_frame_thumbnail "
-                   " where file_id = ? and not (frame_id = ANY(?))")
-          ids (->> (collect-frames data)
-                   (db/create-array conn "uuid"))]
-      ;; delete the unused frame thumbnails
-      (db/exec! conn [sql (:id file) ids]))
-
-    nil))
diff --git a/backend/test/app/services_files_test.clj b/backend/test/app/services_files_test.clj
index 64c69feee..3977a1317 100644
--- a/backend/test/app/services_files_test.clj
+++ b/backend/test/app/services_files_test.clj
@@ -8,6 +8,7 @@
   (:require
    [app.common.uuid :as uuid]
    [app.db :as db]
+   [app.db.sql :as sql]
    [app.http :as http]
    [app.storage :as sto]
    [app.test-helpers :as th]
@@ -117,7 +118,7 @@
           (t/is (= 0 (count result))))))
     ))
 
-(t/deftest file-media-gc-task
+(t/deftest file-gc-task
   (letfn [(create-file-media-object [{:keys [profile-id file-id]}]
             (let [mfile  {:filename "sample.jpg"
                           :path (th/tempfile "app/test_files/sample.jpg")
@@ -130,6 +131,9 @@
                           :name "testfile"
                           :content mfile}
                   out    (th/mutation! params)]
+
+              ;; (th/print-result! out)
+
               (t/is (nil? (:error out)))
               (:result out)))
 
@@ -189,7 +193,7 @@
         (t/is (= 0 (:delete res))))
 
       ;; run the task immediately
-      (let [task  (:app.tasks.file-media-gc/handler th/*system*)
+      (let [task  (:app.tasks.file-gc/handler th/*system*)
             res   (task {})]
         (t/is (= 0 (:processed res))))
 
@@ -198,7 +202,7 @@
       (th/sleep 300)
 
       ;; run the task again
-      (let [task  (:app.tasks.file-media-gc/handler th/*system*)
+      (let [task  (:app.tasks.file-gc/handler th/*system*)
             res   (task {})]
         (t/is (= 1 (:processed res))))
 
@@ -342,7 +346,7 @@
       (t/is (th/ex-info? error))
       (t/is (th/ex-of-type? error :not-found))))
 
-(t/deftest deletion-test
+(t/deftest deletion
   (let [task     (:app.tasks.objects-gc/handler th/*system*)
         profile1 (th/create-profile* 1)
         file     (th/create-file* 1 {:project-id (:default-project-id profile1)
@@ -410,71 +414,158 @@
     ))
 
 (t/deftest query-frame-thumbnails
-  (let [prof  (th/create-profile* 1 {:is-active true})
-        file  (th/create-file* 1 {:profile-id (:id prof)
-                                  :project-id (:default-project-id prof)
-                                  :is-shared false})
-        data {::th/type :file-frame-thumbnail
-              :profile-id (:id prof)
-              :file-id (:id file)
-              :frame-id (uuid/next)}]
-
-    ;;insert an entry on the database with a test value for the thumbnail of this frame
-    (db/exec-one! th/*pool*
-                  ["insert into file_frame_thumbnail(file_id, frame_id, data) values (?, ?, ?)"
-                   (:file-id data) (:frame-id data) "testvalue"])
-
-    (let [out (th/query! data)]
-      (t/is (nil? (:error out)))
-      (let [result (:result out)]
-        (t/is (= 1 (count result)))
-        (t/is (= "testvalue" (:data result)))))))
-
-(t/deftest insert-frame-thumbnails
-  (let [prof    (th/create-profile* 1 {:is-active true})
-        file    (th/create-file* 1 {:profile-id (:id prof)
-                                    :project-id (:default-project-id prof)
-                                    :is-shared false})
-        data {::th/type :upsert-frame-thumbnail
-              :profile-id (:id prof)
-              :file-id (:id file)
-              :frame-id (uuid/next)
-              :data "test insert new value"}
-        out  (th/mutation! data)]
-
-        (t/is (nil? (:error out)))
-        (t/is (nil? (:result out)))
-
-        ;;retrieve the value from the database and check its content
-        (let [result (db/exec-one!
-                      th/*pool*
-                      ["select data from file_frame_thumbnail where file_id = ? and frame_id = ?"
-                       (:file-id data) (:frame-id data)])]
-          (t/is (= "test insert new value" (:data result))))))
-
-(t/deftest frame-thumbnails
   (let [prof (th/create-profile* 1 {:is-active true})
         file (th/create-file* 1 {:profile-id (:id prof)
                                  :project-id (:default-project-id prof)
                                  :is-shared false})
-        data {::th/type :upsert-frame-thumbnail
+        data {::th/type :file-frame-thumbnails
+              :profile-id (:id prof)
+              :file-id (:id file)
+              :frame-id (uuid/next)}]
+
+    ;; insert an entry on the database with a test value for the thumbnail of this frame
+    (th/db-insert! :file-frame-thumbnail
+                   {:file-id (:file-id data)
+                    :frame-id (:frame-id data)
+                    :data "testvalue"})
+
+    (let [{:keys [result error] :as out} (th/query! data)]
+      ;; (th/print-result! out)
+      (t/is (nil? error))
+      (t/is (= 1 (count result)))
+      (t/is (= "testvalue" (get result (:frame-id data)))))))
+
+(t/deftest insert-frame-thumbnails
+  (let [prof (th/create-profile* 1 {:is-active true})
+        file (th/create-file* 1 {:profile-id (:id prof)
+                                 :project-id (:default-project-id prof)
+                                 :is-shared false})
+        data {::th/type :upsert-file-frame-thumbnail
+              :profile-id (:id prof)
+              :file-id (:id file)
+              :frame-id (uuid/next)
+              :data "test insert new value"}]
+
+    (let [out (th/mutation! data)]
+      (t/is (nil? (:error out)))
+      (t/is (nil? (:result out)))
+      (let [[result] (th/db-query :file-frame-thumbnail
+                                  {:file-id (:file-id data)
+                                   :frame-id (:frame-id data)})]
+        (t/is (= "test insert new value" (:data result)))))))
+
+(t/deftest upsert-frame-thumbnails
+  (let [prof (th/create-profile* 1 {:is-active true})
+        file (th/create-file* 1 {:profile-id (:id prof)
+                                 :project-id (:default-project-id prof)
+                                 :is-shared false})
+        data {::th/type :upsert-file-frame-thumbnail
               :profile-id (:id prof)
               :file-id (:id file)
               :frame-id (uuid/next)
               :data "updated value"}]
 
-    ;;insert an entry on the database with and old value for the thumbnail of this frame
-    (db/exec-one! th/*pool*
-                  ["insert into file_frame_thumbnail(file_id, frame_id, data) values (?, ?, ?)"
-                   (:file-id data) (:frame-id data) "old value"])
+    ;; insert an entry on the database with and old value for the thumbnail of this frame
+    (th/db-insert! :file-frame-thumbnail
+                   {:file-id (:file-id data)
+                    :frame-id (:frame-id data)
+                    :data "old value"})
 
     (let [out (th/mutation! data)]
+      ;; (th/print-result! out)
+
       (t/is (nil? (:error out)))
       (t/is (nil? (:result out)))
 
-      ;;retrieve the value from the database and check its content
-      (let [result (db/exec-one!
-                    th/*pool*
-                    ["select data from file_frame_thumbnail where file_id = ? and frame_id = ?"
-                     (:file-id data) (:frame-id data)])]
+      ;; retrieve the value from the database and check its content
+      (let [[result] (th/db-query :file-frame-thumbnail
+                                  {:file-id (:file-id data)
+                                   :frame-id (:frame-id data)})]
         (t/is (= "updated value" (:data result)))))))
+
+
+(t/deftest file-thumbnail-ops
+  (let [prof (th/create-profile* 1 {:is-active true})
+        file (th/create-file* 1 {:profile-id (:id prof)
+                                 :project-id (:default-project-id prof)
+                                 :revn 2
+                                 :is-shared false})
+        data {::th/type :file-thumbnail
+              :profile-id (:id prof)
+              :file-id (:id file)}]
+
+    (t/testing "query a thumbnail with single revn"
+
+      ;; insert an entry on the database with a test value for the thumbnail of this frame
+      (th/db-insert! :file-thumbnail
+                     {:file-id (:file-id data)
+                      :revn 1
+                      :data "testvalue1"})
+
+      (let [{:keys [result error] :as out} (th/query! data)]
+        ;; (th/print-result! out)
+        (t/is (nil? error))
+        (t/is (= 4 (count result)))
+        (t/is (= "testvalue1" (:data result)))
+        (t/is (= 1 (:revn result)))))
+
+    (t/testing "query thumbnail with two revisions"
+      ;; insert an entry on the database with a test value for the thumbnail of this frame
+      (th/db-insert! :file-thumbnail
+                     {:file-id (:file-id data)
+                      :revn 2
+                      :data "testvalue2"})
+
+      (let [{:keys [result error] :as out} (th/query! data)]
+        ;; (th/print-result! out)
+        (t/is (nil? error))
+        (t/is (= 4 (count result)))
+        (t/is (= "testvalue2" (:data result)))
+        (t/is (= 2 (:revn result))))
+
+      ;; Then query the specific revn
+      (let [{:keys [result error] :as out} (th/query! (assoc data :revn 1))]
+        ;; (th/print-result! out)
+        (t/is (nil? error))
+        (t/is (= 4 (count result)))
+        (t/is (= "testvalue1" (:data result)))
+        (t/is (= 1 (:revn result)))))
+
+    (t/testing "upsert file-thumbnail"
+      (let [data {::th/type :upsert-file-thumbnail
+                  :profile-id (:id prof)
+                  :file-id (:id file)
+                  :data "foobar"
+                  :props {:baz 1}
+                  :revn 2}
+            {:keys [result error] :as out} (th/mutation! data)]
+        ;; (th/print-result! out)
+        (t/is (nil? error))
+        (t/is (nil? result))))
+
+    (t/testing "query last result"
+      (let [{:keys [result error] :as out} (th/query! data)]
+        ;; (th/print-result! out)
+        (t/is (nil? error))
+        (t/is (= 4 (count result)))
+        (t/is (= "foobar" (:data result)))
+        (t/is (= {:baz 1} (:props result)))
+        (t/is (= 2 (:revn result)))))
+
+    (t/testing "gc task"
+      ;; make the file eligible for GC waiting 300ms (configured
+      ;; timeout for testing)
+      (th/sleep 300)
+
+      ;; run the task again
+      (let [task  (:app.tasks.file-gc/handler th/*system*)
+            res   (task {})]
+        (t/is (= 1 (:processed res))))
+
+      ;; Then query the specific revn
+      (let [{:keys [result error] :as out} (th/query! (assoc data :revn 1))]
+        (t/is (= :not-found (th/ex-type error)))
+        (t/is (= :file-thumbnail-not-found (th/ex-code error)))))
+    ))
+
+
diff --git a/backend/test/app/test_helpers.clj b/backend/test/app/test_helpers.clj
index e626f4dd1..5699424a6 100644
--- a/backend/test/app/test_helpers.clj
+++ b/backend/test/app/test_helpers.clj
@@ -73,7 +73,7 @@
                            :app.worker/cron
                            :app.worker/worker)
                    (d/deep-merge
-                    {:app.tasks.file-media-gc/handler {:max-age (dt/duration 300)}}))
+                    {:app.tasks.file-gc/handler {:max-age (dt/duration 300)}}))
         _      (ig/load-namespaces config)
         system (-> (ig/prep config)
                    (ig/init))]
@@ -285,7 +285,8 @@
   (let [data (ex-data error)]
     (cond
       (= :spec-validation (:code data))
-      (expound/printer (:data data))
+      (println
+       (us/pretty-explain data))
 
       (= :service-error (:type data))
       (print-error! (.getCause ^Throwable error))
@@ -302,7 +303,7 @@
       (println "====> END ERROR"))
     (do
       (println "====> START RESPONSE")
-      (prn result)
+      (fipp.edn/pprint result)
       (println "====> END RESPONSE"))))
 
 (defn exception?
@@ -374,3 +375,15 @@
     (.readLine cnsl)
     nil))
 
+(defn db-exec!
+  [sql]
+  (db/exec! *pool* sql))
+
+(defn db-insert!
+  [& params]
+  (apply db/insert! *pool* params))
+
+(defn db-query
+  [& params]
+  (apply db/query *pool* params))
+
diff --git a/common/src/app/common/data.cljc b/common/src/app/common/data.cljc
index 08c952d93..77f39b694 100644
--- a/common/src/app/common/data.cljc
+++ b/common/src/app/common/data.cljc
@@ -128,9 +128,10 @@
 (defn index-by
   "Return a indexed map of the collection keyed by the result of
   executing the getter over each element of the collection."
-  [getter coll]
-  (persistent!
-   (reduce #(assoc! %1 (getter %2) %2) (transient {}) coll)))
+  ([kf coll] (index-by kf identity coll))
+  ([kf vf coll]
+   (persistent!
+    (reduce #(assoc! %1 (kf %2) (vf %2)) (transient {}) coll))))
 
 (defn index-of-pred
   [coll pred]