X-Git-Url: https://git.arvados.org/arvados.git/blobdiff_plain/7407f41105f8000bb3908d41a31daaf3a30d9440..c7dfdc3f58e993abad5ef7fb898ac137cca62e02:/services/api/lib/update_permissions.rb

diff --git a/services/api/lib/update_permissions.rb b/services/api/lib/update_permissions.rb
index 7b1b900cac..23e60c8ed9 100644
--- a/services/api/lib/update_permissions.rb
+++ b/services/api/lib/update_permissions.rb
@@ -62,10 +62,12 @@ def update_permissions perm_origin_uuid, starting_uuid, perm_level, edge_id=nil
 
   ActiveRecord::Base.transaction do
 
-    # "Conflicts with the ROW EXCLUSIVE, SHARE UPDATE EXCLUSIVE, SHARE
-    # ROW EXCLUSIVE, EXCLUSIVE, and ACCESS EXCLUSIVE lock modes. This
-    # mode protects a table against concurrent data changes."
-    ActiveRecord::Base.connection.execute "LOCK TABLE #{PERMISSION_VIEW} in SHARE MODE"
+    # "Conflicts with the ROW SHARE, ROW EXCLUSIVE, SHARE UPDATE
+    # EXCLUSIVE, SHARE, SHARE ROW EXCLUSIVE, EXCLUSIVE, and ACCESS
+    # EXCLUSIVE lock modes. This mode allows only concurrent ACCESS
+    # SHARE locks, i.e., only reads from the table can proceed in
+    # parallel with a transaction holding this lock mode."
+    ActiveRecord::Base.connection.execute "LOCK TABLE #{PERMISSION_VIEW} in EXCLUSIVE MODE"
 
     # Workaround for
     # BUG #15160: planner overestimates number of rows in join when there are more than 200 rows coming from CTE