had this happen in the middle of a remap:
… Remapping posts raw 1454 rows affected! Remapping posts cooked Error: ERROR: deadlock detected DETAIL: Process 10050 waits for ShareLock on transaction 552065959; blocked by process 9965. Process 9965 waits for ShareLock on transaction 552065918; blocked by process 10050. HINT: See server log for query details. CONTEXT: while rechecking updated tuple (59101,9) in relation "posts" Remapping posts edit_reason 0 rows affected! Remapping posts raw_email 4340 rows affected! Remapping posts action_code 0 rows affected! Remapping posts image_url 122356 rows affected! …continues…
Good thing I was watching it or I wouldn’t have known!
discourse remap should retry and abort the entire process if it cannot succeed