Re: pg_restore dependencies

Tom Lane wrote:
> Andrew Dunstan <andrew@dunslane.net> writes:
>   
>> We still have a little work to do on dependencies in parallel 
>> pg_restore. The current test compares the candidate's locking 
>> dependencies with those of the running jobs, and allows the candidate is 
>> there isn't a match. That's not a broad enough test. The candidate will 
>> block if there's a currently running CREATE INDEX command on the table, 
>> for example, even though that doesn't require an exclusive lock. That's 
>> not catastrophic, in that the restore doesn't fail, but it's fairly bad 
>> because it reduces the achievable parallelism. Josh Berkus observed this 
>> during testing on a very large restore.
>>     
>
> Well, we certainly want to be able to run CREATE INDEXes in parallel,
> so this would appear to require hard-wiring some conception of shared
> versus exclusive lock into pg_restore.  I think it might be a bit late
> to consider that for 8.4.
>   


I'm pretty sure I had the logic for this correct stuff originally, so 
I'm going to go back and check that.

With luck it won't take long. It shouldn't hold up beta - it's just a 
bug we need to fix, and with any luck I'll actually have it fixed in the 
next few days.


cheers

andrew