Neil Conway wrote: > Magnus Hagander wrote: >> Anyway. Attached patch adds this to the bgwriter shared memory. Is it >> safe to do this, and then just have a regular function running in a >> normal backend pulling out the value and returning it to the user, >> without locking? > If the variable is an int64, I don't believe so: the architecture might > not implement atomic read/writes of int64 values.
Ok. But it should be safe if it's int32? Actually, since it's just statistics data, it wouldn't be a problem that it's not atomic, I think. If we really unlucky, we'll get the wrong value once. But most systems that poll such statistics can deal with that, in my experience. Then again, a normal int shouldn't be a problem either. //Magnus ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match