diff --git a/swh/provenance/postgresql/provenance.py b/swh/provenance/postgresql/provenance.py
--- a/swh/provenance/postgresql/provenance.py
+++ b/swh/provenance/postgresql/provenance.py
@@ -93,7 +93,6 @@
         try:
             if urls:
                 sql = """
-                    LOCK TABLE ONLY origin;
                     INSERT INTO origin(sha1, url) VALUES %s
                       ON CONFLICT DO NOTHING
                     """
@@ -128,7 +127,6 @@
         try:
             if origins:
                 sql = """
-                    LOCK TABLE ONLY revision;
                     INSERT INTO revision(sha1, origin)
                       (SELECT V.rev AS sha1, O.id AS origin
                        FROM (VALUES %s) AS V(rev, org)
@@ -178,7 +176,6 @@
                     # non-null information
                     srcs = tuple(set((sha1,) for (sha1, _, _) in rows))
                     sql = f"""
-                        LOCK TABLE ONLY {src_table};
                         INSERT INTO {src_table}(sha1) VALUES %s
                           ON CONFLICT DO NOTHING
                         """
@@ -189,7 +186,6 @@
                     # non-null information
                     dsts = tuple(set((sha1,) for (_, sha1, _) in rows))
                     sql = f"""
-                        LOCK TABLE ONLY {dst_table};
                         INSERT INTO {dst_table}(sha1) VALUES %s
                           ON CONFLICT DO NOTHING
                         """
@@ -254,7 +250,6 @@
         try:
             if data:
                 sql = f"""
-                    LOCK TABLE ONLY {entity};
                     INSERT INTO {entity}(sha1, date) VALUES %s
                       ON CONFLICT (sha1) DO
                       UPDATE SET date=LEAST(EXCLUDED.date,{entity}.date)
diff --git a/swh/provenance/sql/40-funcs.sql b/swh/provenance/sql/40-funcs.sql
--- a/swh/provenance/sql/40-funcs.sql
+++ b/swh/provenance/sql/40-funcs.sql
@@ -99,7 +99,6 @@
         join_location text;
     begin
         if src_table in ('content'::regclass, 'directory'::regclass) then
-            lock table only location;
             insert into location(path)
               select V.path
               from tmp_relation_add as V
@@ -113,15 +112,14 @@
         end if;
 
         execute format(
-            'lock table only %s;
-             insert into %s
+            'insert into %s
                select S.id, ' || select_fields || '
                from tmp_relation_add as V
                inner join %s as S on (S.sha1 = V.src)
                inner join %s as D on (D.sha1 = V.dst)
                ' || join_location || '
              on conflict do nothing',
-            rel_table, rel_table, src_table, dst_table
+            rel_table, src_table, dst_table
         );
     end;
 $$;
@@ -254,14 +252,13 @@
 as $$
     begin
         execute format(
-            'lock table only %s;
-             insert into %s
+            'insert into %s
                select S.id, D.id
                from tmp_relation_add as V
                inner join %s as S on (S.sha1 = V.src)
                inner join %s as D on (D.sha1 = V.dst)
              on conflict do nothing',
-            rel_table, rel_table, src_table, dst_table
+            rel_table, src_table, dst_table
         );
     end;
 $$;
@@ -422,7 +419,6 @@
         on_conflict text;
     begin
         if src_table in ('content'::regclass, 'directory'::regclass) then
-            lock table only location;
             insert into location(path)
               select V.path
               from tmp_relation_add as V
@@ -448,8 +444,7 @@
         end if;
 
         execute format(
-            'lock table only %s;
-             insert into %s
+            'insert into %s
                select S.id, ' || select_fields || '
                from tmp_relation_add as V
                inner join %s as S on (S.sha1 = V.src)
@@ -457,7 +452,7 @@
                ' || join_location || '
                ' || group_entries || '
              on conflict ' || on_conflict,
-            rel_table, rel_table, src_table, dst_table
+            rel_table, src_table, dst_table
         );
     end;
 $$;
@@ -641,15 +636,14 @@
         end if;
 
         execute format(
-            'lock table only %s;
-             insert into %s
+            'insert into %s
                select S.id, ' || select_fields || '
                from tmp_relation_add as V
                inner join %s as S on (S.sha1 = V.src)
                inner join %s as D on (D.sha1 = V.dst)
                ' || group_entries || '
              on conflict ' || on_conflict,
-            rel_table, rel_table, src_table, dst_table
+            rel_table, src_table, dst_table
         );
     end;
 $$;