| From: | Jim Nasby <jim(at)nasby(dot)net> |
|---|---|
| To: | Andres Freund <andres(at)2ndquadrant(dot)com> |
| Cc: | Robert Haas <robertmhaas(at)gmail(dot)com>, Erik Rijkers <er(at)xs4all(dot)nl>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org> |
| Subject: | Re: Changeset Extraction v7.6.1 |
| Date: | 2014-06-01 05:50:58 |
| Message-ID: | 538ABF42.9040106@nasby.net |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers |
On 5/31/14, 9:11 AM, Andres Freund wrote:
> 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.
Just keep in mind that one of the use cases for logical replication is upgrades.
--
Jim C. Nasby, Data Architect jim(at)nasby(dot)net
512.569.9461 (cell) http://jim.nasby.net
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Andres Freund | 2014-06-01 05:57:32 | Re: Changeset Extraction v7.6.1 |
| Previous Message | Claudio Freire | 2014-06-01 05:27:11 | Re: Extended Prefetching using Asynchronous IO - proposal and patch |