I'm trying to understand what a soft deadlock is as described by deadlock.c.
As best I understand if a process, A, is waiting for a lock and is being blocked only because someone, B, is ahead of it in the queue but hasn't been granted the conflicting lock we want to jump A ahead of B. So if i do something like: process X: --------- select * from x where i=1 for share; ---------------- process B: --------- select * from x where i=1 for update; ---------------- process A: --------- select * from x where i=1 for share; process A will block, but when the deadlock timeout fires it should get jumped ahead of process B. If that's right then, uh, it doesn't seem to be working. Process B: postgres=# select * from x where i = 0 for update; LOG: process 4629 still waiting for ShareLock on transaction 7802 after 5000.149 ms Process A: postgres=# select * from x where i = 0 for share; LOG: process 4631 still waiting for ShareLock on tuple (0,1) of relation 16423 of database 11408 after 5000.151 ms -- Gregory Stark EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
