diff --git a/sql/upgrades/179.sql b/sql/upgrades/179.sql
new file mode 100644
--- /dev/null
+++ b/sql/upgrades/179.sql
@@ -0,0 +1,9 @@
+-- SWH DB schema upgrade
+-- from_version: 178
+-- to_version: 179
+-- description: add bzr to revision_type values
+
+insert into dbversion(version, release, description)
+      values(179, now(), 'Work In Progress');
+
+alter table release drop constraint release_author_date_check;
diff --git a/swh/storage/postgresql/db.py b/swh/storage/postgresql/db.py
--- a/swh/storage/postgresql/db.py
+++ b/swh/storage/postgresql/db.py
@@ -30,7 +30,7 @@
 
     """
 
-    current_version = 178
+    current_version = 179
 
     def mktemp_dir_entry(self, entry_type, cur=None):
         self._cursor(cur).execute(
diff --git a/swh/storage/sql/30-schema.sql b/swh/storage/sql/30-schema.sql
--- a/swh/storage/sql/30-schema.sql
+++ b/swh/storage/sql/30-schema.sql
@@ -17,7 +17,7 @@
 
 -- latest schema version
 insert into dbversion(version, release, description)
-      values(178, now(), 'Work In Progress');
+      values(179, now(), 'Work In Progress');
 
 -- a SHA1 checksum
 create domain sha1 as bytea check (length(value) = 20);
diff --git a/swh/storage/sql/60-indexes.sql b/swh/storage/sql/60-indexes.sql
--- a/swh/storage/sql/60-indexes.sql
+++ b/swh/storage/sql/60-indexes.sql
@@ -236,10 +236,6 @@
 
   alter table release
     validate constraint release_date_neg_utc_offset_not_null;
-
-  -- if the author is null, then the date must be null
-  alter table release add constraint release_author_date_check check ((date is null) or (author is not null)) not valid;
-  alter table release validate constraint release_author_date_check;
 \endif
 
 -- metadata_fetcher