Hi there, Pls find following error log in our Azure data sync group. Tracing ID ‘d913edcf-e15d-452f-981d-504fa3bb47f7’ > Tombstone cleanup failed with the exception "SqlException Error Code: -2146232060 - SqlError Number:1205, Message: Transaction (Process ID 64) was deadlocked on lock | communication buffer resources with another process and has been chosen as the deadlock victim. Rerun the transaction. For more information, provide tracing ID ‘d913edcf-e15d-452f-981d-504fa3bb47f7’ to customer support. Meanwhile, we found many oversized side(*_dss_tracking) tables in our db. The performance for sync to on-premise db is also not efficient. Many sync_row_is_tombstone exist in side table. ![45582-image.png][1] [1]: /api/attachments/45582-image.png?platform=QnA