Re: parallel restore item dependencies

Andrew Dunstan <andrew@dunslane.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