While reading this thread, I thought of two things I think we could do
if this feature was implemented:
1. Sort large UPDATE/DELETEs so it is done in heap order
This is actually a TODO item. I imagine it would be possible to do
something like:
DELETE FROM foo USING (...) ORDER BY ctid;
with this patch to help this case.
2. Reducing deadlocks in big UPDATE/DELETEs
One problem that sometimes occurs when doing multiple multi-row UPDATEs
or DELETEs concurrently is that the transactions end up working on the
same rows, but in a different order. One could use an ORDER BY clause
to make sure the transactions don't deadlock.
Thoughts?
Regards,
Marko Tiikkaja
