On 9/8/2004 1:51 PM, Ed L. wrote:

> On Monday September 6 2004 4:20, Christopher Browne wrote:
>> And the real problem would most likely come in the initial "seeding."
>> When you provision a new subscriber, it has to take on _all_ of the data
>> then sitting at its provider, all in one transaction.  That takes a
>> while, across a slow link, and if that link is not sufficiently reliable,
>> you might never get the first "sync."
> 
> Our typical DB is around 10GB.  Do I understand correctly that the first 
> seeding transfer will include all of the 10GB in one very large, very long 
> transaction on the slave?  Any concerns about that much data going across?

Why would that concern you?

> 
> And the path traveled is from provider pgsql to provider slon to subscriber 
> slon to subscriber pgsql?  Any concerns there about memory needs?  Or is it 
> pipelined in transfer?

The subscriber slon has a DB connection to the provider and the local 
subscriber DB. It does "COPY foo TO stdout" on the provider and on the 
subscriber DB "COPY foo FROM stdin", then it forwards the entire data in 
chunks via PQgetCopyData(), PQputCopyData(). I didn't bother to 
multithread that process.


Jan

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