Re: parallel restore item dependencies

Andrew Dunstan <andrew(at)dunslane(dot)net> writes:
> OK, I've worked out why I am seeing deadlocks etc. from parallel restore
> on FK items.

> In my original patch, I looked at all the dependencies of a candidate
> item ansd compared them with the dependencies of the running items to
> see if there was a potential locking clash. However, Tom in his
> admirable reworking of my patch, restricted the list of potential
> clashing items (lockDeps) to "TABLE" items, if any. This would probably
> have been ok if we hadn't just beforehand transferred all TABLE
> dependencies in POST_DATA items to the corresponding TABLE DATA item.
> The result is that we get empty lockDeps lists on all items - I'm
> surprised we haven't had more complaints about deadlock or failing locks.

[ scratches head... ] I coulda sworn I tested that when I was hacking
it. I'm running low on steam tonight but will think more about this
tomorrow.

regards, tom lane