Re: Changeset Extraction v7.6.1

On 2014-02-21 15:14:15 -0600, Jim Nasby wrote:
> On 2/17/14, 7:31 PM, Robert Haas wrote:
> >But do you really want to keep that snapshot around long enough to
> >copy the entire database?  I bet you don't: if the database is big,
> >holding back xmin for long enough to copy the whole thing isn't likely
> >to be fun.
> 
> I can confirm that this would be epic fail, at least for londiste. It takes about 3 weeks for a new copy of a ~2TB
database.There's no way that'd work with one snapshot. (Granted, copy performance in londiste is rather lackluster, but
still...)

I'd marked this email as todo:
If you have such a huge database you can, with logical decoding at
least, use a basebackup using pg_basebackup or pg_start/stop_backup()
and roll forwards from that... That'll hopefull make such huge copies
much faster.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
Services