diff --git a/swh/storage/archiver/db.py b/swh/storage/archiver/db.py
index 30b4e3f7..2b348291 100644
--- a/swh/storage/archiver/db.py
+++ b/swh/storage/archiver/db.py
@@ -1,269 +1,275 @@
 # Copyright (C) 2015-2017  The Software Heritage developers
 # See the AUTHORS file at the top-level directory of this distribution
 # License: GNU General Public License version 3, or any later version
 # See top-level LICENSE file for more information
 
 
 import json
 import time
 
 from swh.core import hashutil
 from swh.storage.db import BaseDb, cursor_to_bytes, stored_procedure
 
 
 class ArchiverDb(BaseDb):
     """Proxy to the SWH's archiver DB
 
     """
 
     def archive_ls(self, cur=None):
         """ Get all the archives registered on the server.
 
         Yields:
             a tuple (server_id, server_url) for each archive server.
         """
         cur = self._cursor(cur)
         cur.execute("SELECT * FROM archive")
         yield from cursor_to_bytes(cur)
 
     def content_archive_get(self, content_id, cur=None):
         """ Get the archival status of a content in a specific server.
 
         Retrieve from the database the archival status of the given content
         in the given archive server.
 
         Args:
             content_id: the sha1 of the content.
 
         Yields:
             A tuple (content_id, present_copies, ongoing_copies), where
             ongoing_copies is a dict mapping copy to mtime.
         """
         query = """SELECT content_id,
                           array(
                             SELECT key
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'present'
                             ORDER BY key
                           ) AS present,
                           array(
                             SELECT key
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'ongoing'
                             ORDER BY key
                           ) AS ongoing,
                           array(
                             SELECT value->'mtime'
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'ongoing'
                             ORDER BY key
                           ) AS ongoing_mtime
                    FROM content_archive
                    WHERE content_id = %s
                    ORDER BY content_id
         """
         cur = self._cursor(cur)
         cur.execute(query, (content_id,))
         row = cur.fetchone()
         if not row:
             return None
         content_id, present, ongoing, mtimes = row
         return (content_id, present, dict(zip(ongoing, mtimes)))
 
     def content_archive_get_copies(self, last_content=None, limit=1000,
                                    cur=None):
         """Get the list of copies for `limit` contents starting after
            `last_content`.
 
         Args:
             last_content: sha1 of the last content retrieved. May be None
                               to start at the beginning.
             limit: number of contents to retrieve. Can be None to retrieve all
                    objects (will be slow).
 
         Yields:
             A tuple (content_id, present_copies, ongoing_copies), where
             ongoing_copies is a dict mapping copy to mtime.
 
         """
 
         query = """SELECT content_id,
                           array(
                             SELECT key
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'present'
                             ORDER BY key
                           ) AS present,
                           array(
                             SELECT key
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'ongoing'
                             ORDER BY key
                           ) AS ongoing,
                           array(
                             SELECT value->'mtime'
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'ongoing'
                             ORDER BY key
                           ) AS ongoing_mtime
                    FROM content_archive
                    WHERE content_id > %s
                    ORDER BY content_id
                    LIMIT %s
         """
 
         if last_content is None:
             last_content = b''
 
         cur = self._cursor(cur)
         cur.execute(query, (last_content, limit))
         for content_id, present, ongoing, mtimes in cursor_to_bytes(cur):
             yield (content_id, present, dict(zip(ongoing, mtimes)))
 
     def content_archive_get_unarchived_copies(
             self, retention_policy, last_content=None,
             limit=1000, cur=None):
         """ Get the list of copies for `limit` contents starting after
             `last_content`. Yields only copies with number of present
             smaller than `retention policy`.
 
         Args:
             last_content: sha1 of the last content retrieved. May be None
                               to start at the beginning.
             retention_policy: number of required present copies
             limit: number of contents to retrieve. Can be None to retrieve all
                    objects (will be slow).
 
         Yields:
             A tuple (content_id, present_copies, ongoing_copies), where
             ongoing_copies is a dict mapping copy to mtime.
 
         """
 
         query = """SELECT content_id,
                           array(
                             SELECT key
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'present'
                             ORDER BY key
                           ) AS present,
                           array(
                             SELECT key
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'ongoing'
                             ORDER BY key
                           ) AS ongoing,
                           array(
                             SELECT value->'mtime'
                             FROM jsonb_each(copies)
                             WHERE value->>'status' = 'ongoing'
                             ORDER BY key
                           ) AS ongoing_mtime
                    FROM content_archive
                    WHERE content_id > %s AND num_present < %s
                    ORDER BY content_id
                    LIMIT %s
         """
 
         if last_content is None:
             last_content = b''
 
         cur = self._cursor(cur)
         cur.execute(query, (last_content, retention_policy, limit))
         for content_id, present, ongoing, mtimes in cursor_to_bytes(cur):
             yield (content_id, present, dict(zip(ongoing, mtimes)))
 
     @stored_procedure('swh_mktemp_content_archive')
     def mktemp_content_archive(self, cur=None):
         """Trigger the creation of the temporary table tmp_content_archive
         during the lifetime of the transaction.
 
         Use from archiver.storage module:
             self.db.mktemp_content_archive()
             # copy data over to the temp table
             self.db.copy_to([{'colname': id0}, {'colname': id1}],
                             'tmp_cache_content',
                             ['colname'], cur)
 
         """
         pass
 
     def content_archive_get_missing(self, backend_name, cur=None):
         """Retrieve the content missing from backend_name.
 
         """
         cur = self._cursor(cur)
         cur.execute("select * from swh_content_archive_missing(%s)",
                     (backend_name,))
         yield from cursor_to_bytes(cur)
 
     def content_archive_get_unknown(self, cur=None):
         """Retrieve unknown sha1 from archiver db.
 
         """
         cur = self._cursor(cur)
         cur.execute('select * from swh_content_archive_unknown()')
         yield from cursor_to_bytes(cur)
 
     def content_archive_update(self, content_id, archive_id,
                                new_status=None, cur=None):
         """ Update the status of an archive content and set its mtime to
 
         Change the mtime of an archived content for the given archive and set
         it's mtime to the current time.
 
         Args:
             content_id (str): content sha1
             archive_id (str): name of the archive
             new_status (str): one of 'missing', 'present' or 'ongoing'.
                 this status will replace the previous one. If not given,
                 the function only change the mtime of the content for the
                 given archive.
         """
         if isinstance(content_id, bytes):
             content_id = '\\x%s' % hashutil.hash_to_hex(content_id)
 
         if new_status is not None:
             query = """UPDATE content_archive
                     SET copies=jsonb_set(
                         copies, '{%s}',
                         '{"status":"%s", "mtime":%d}'
                     )
                     WHERE content_id='%s'
                     """ % (archive_id,
                            new_status, int(time.time()),
                            content_id)
         else:
             query = """ UPDATE content_archive
                     SET copies=jsonb_set(copies, '{%s,mtime}', '%d')
                     WHERE content_id='%s'
                     """ % (archive_id, int(time.time()))
 
         cur = self._cursor(cur)
         cur.execute(query)
 
     def content_archive_add(
             self, content_id, sources_present, sources_missing, cur=None):
+        """Add content archive entry for the content content_id.
+        The status is:
+        - present for all sources in sources_present.
+        - missing for all sources in sources_missing.
+
+        """
 
         if isinstance(content_id, bytes):
             content_id = '\\x%s' % hashutil.hash_to_hex(content_id)
 
         copies = {}
         num_present = 0
         for source in sources_present:
             copies[source] = {
                 "status": "present",
                 "mtime": int(time.time()),
             }
             num_present += 1
 
         for source in sources_missing:
             copies[source] = {
-                "status": "absent",
+                "status": "missing",
             }
 
         query = """INSERT INTO content_archive(content_id, copies, num_present)
                    VALUES('%s', '%s', %s)
                 """ % (content_id, json.dumps(copies), num_present)
         cur = self._cursor(cur)
         cur.execute(query)