diff --git a/http/autocomplete.py b/http/autocomplete.py
index 4f7a692..9d0bd5c 100755
--- a/http/autocomplete.py
+++ b/http/autocomplete.py
@@ -18,10 +18,12 @@
 #  You should have received a copy of the GNU Affero General Public License
 #  along with Elixir.  If not, see <http://www.gnu.org/licenses/>.
 
-import falcon
-from urllib import parse
 import sys
 import os
+import json
+from urllib import parse
+from bsddb3.db import DB_SET_RANGE
+import falcon
 
 ELIXIR_DIR = os.path.dirname(os.path.realpath(__file__)) + '/..'
 
@@ -29,6 +31,7 @@ if ELIXIR_DIR not in sys.path:
     sys.path = [ ELIXIR_DIR ] + sys.path
 
 import query
+from lib import autoBytes
 
 class AutocompleteResource:
     def on_get(self, req, resp):
@@ -44,57 +47,42 @@ class AutocompleteResource:
 
         q = query.Query(datadir, repodir)
 
-        # Create tmp directory for autocomplete
-        tmpdir = '/tmp/autocomplete/' + query_project
-        if not(os.path.isdir(tmpdir)):
-            os.makedirs(tmpdir, exist_ok=True)
-
         latest = q.query('latest')
 
-        # Define some specific values for some families
         if query_family == 'B':
-            name = 'comps'
+            # DTS identifiers are stored quoted
             process = lambda x: parse.unquote(x)
+            db = q.db.comps
         else:
-            name = 'defs'
             process = lambda x: x
+            db = q.db.defs
 
-        # Init values for tmp files
-        filename = tmpdir + '/' + name
-        mode = 'r+' if os.path.exists(filename) else 'w+'
+        response = []
 
-        # Open tmp file
-        # Fill it with the keys of the database only
-        # if the file is older than the database
-        f = open(filename, mode)
-        if not f.readline()[:-1] == latest:
-            f.seek(0)
-            f.truncate()
-            f.write(latest + "\n")
-            f.write('\n'.join([process(x.decode()) for x in q.query('keys', name)]))
-            f.seek(0)
-            f.readline() # Skip first line that store the version number
-
-        # Prepare http response
-        response = '['
-
-        # Search for the 10 first matching elements in the tmp file
-        index = 0
-        for i in f:
-            if i.startswith(query_string):
-                response += '"' + i[:-1] + '",'
-                index += 1
-
-            if index == 10:
+        i = 0
+        cur = db.db.cursor()
+        query_bytes = autoBytes(parse.quote(query_string))
+        # Find "the smallest key greater than or equal to the specified key"
+        # https://docs.oracle.com/cd/E17276_01/html/api_reference/C/dbcget.html
+        # In practice this should mean "the key that starts with provided prefix"
+        # See docs about the default comparison function for B-Tree databases:
+        # https://docs.oracle.com/cd/E17276_01/html/api_reference/C/dbset_bt_compare.html
+        key, _ = cur.get(query_bytes, DB_SET_RANGE)
+        while i <= 10:
+            if key.startswith(query_bytes):
+                # If found key starts with the prefix, add to response
+                # and move to the next key
+                i += 1
+                response.append(process(key.decode("utf-8")))
+                key, _ = cur.next()
+            else:
+                # If found key does not start with the prefix, stop
                 break
 
-        # Complete and send response
-        response = response[:-1] + ']'
-        resp.text = response
         resp.status = falcon.HTTP_200
+        resp.content_type = falcon.MEDIA_JSON
+        resp.media = response
 
-        # Close tmp file
-        f.close()
 
 def get_application():
     app = falcon.App()