Gaviun,

> We can run this script again and again, and after a few seconds get a deadlock on a different table each time. The really annoying thing here is the deadlocked table isn't even one we want to ALTER. Is there anything we can do here except for 'try again at 4am when things are quiet'?

>From what I understood, slony will lock all tables in the set and remove
the slony triggers before executing the script. It cannot possibly know
which tables will be modified by the script, and it must lock the tables
so nobody touches them between dropping the slony trigger, executing the
script and recreating the slony triggers. So it locks all the tables in
the set, in the order you defined them in the set. If you have
concurrently running transactions which lock tables in other order, you
can easily get deadlocks...

So very likely the answer is do it at 4AM.

Cheers,
Csaba.