Alban Hertroys skrev: > Nis Jørgensen wrote: >> If you can't wait, you are probably better off working around the >> problem. Standard solution is to do: >> >> UPDATE master SET m2 = -m2; >> UPDATE master SET m2 = -m2+1; >> >> or something similar. > > Would something like > > UPDATE master set m2 = master2.m2 > FROM ( > SELECT m2 +1 > FROM master m > WHERE m.master_id = master.master_id > ORDER BY m2 DESC > ) master2 > > work? I think it might be faster (and possibly cause less index bloat) > than doing two consequent updates.
I don't understand your query. I don't think you can use a correlated subquery in that way. Anyway, tricks like these might work. They might stop working without warning, if the plan changes. Relying on unspecified behavior is a recipe for trouble. Nis ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
