Re: WIP patch for parallel pg_dump

On 12/02/2010 05:32 PM, Tom Lane wrote:
> Andrew Dunstan<andrew@dunslane.net>  writes:
>> On 12/02/2010 05:01 PM, Tom Lane wrote:
>>> In the past, proposals for this have always been rejected on the grounds
>>> that it's impossible to assure a consistent dump if different
>>> connections are used to read different tables.  I fail to understand
>>> why that consideration can be allowed to go by the wayside now.
>> Well, snapshot cloning should allow that objection to be overcome, no?
> Possibly, but we need to see that patch first not second.

Yes, I agree with that.

> (I'm not actually convinced that snapshot cloning is the only problem
> here; locking could be an issue too, if there are concurrent processes
> trying to take locks that will conflict with pg_dump's.  But the
> snapshot issue is definitely a showstopper.)
>
>             


Why is that more an issue with parallel pg_dump?

cheers

andrew