| From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
|---|---|
| To: | "Jim C(dot) Nasby" <jim(at)nasby(dot)net> |
| Cc: | Simon Riggs <simon(at)2ndquadrant(dot)com>, pgsql-hackers(at)postgresql(dot)org, Heikki Linnakangas <heikki(at)enterprisedb(dot)com>, pgsql-patches(at)postgresql(dot)org |
| Subject: | Re: [HACKERS] Incrementally Updated Backup |
| Date: | 2006-09-20 21:50:48 |
| Message-ID: | 19737.1158789048@sss.pgh.pa.us |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-hackers pgsql-patches |
"Jim C. Nasby" <jim(at)nasby(dot)net> writes:
> My thought is that in many envoronments it would take much beefier
> hardware to support N postmasters running simultaneously than to cycle
> through them periodically bringing the backups up-to-date.
How you figure that? The cycling approach will require more total I/O
due to extra page re-reads ... particularly if it's built on a patch
like this one that abandons work-in-progress at arbitrary points.
A postmaster running WAL replay does not require all that much in the
way of CPU resources. It is going to need I/O comparable to the gross
I/O load of its master, but cycling isn't going to reduce that at all.
regards, tom lane
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Jim C. Nasby | 2006-09-20 22:07:29 | Re: [HACKERS] Incrementally Updated Backup |
| Previous Message | Jim C. Nasby | 2006-09-20 21:44:32 | Re: [HACKERS] Incrementally Updated Backup |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Jim C. Nasby | 2006-09-20 22:07:29 | Re: [HACKERS] Incrementally Updated Backup |
| Previous Message | Jim C. Nasby | 2006-09-20 21:44:32 | Re: [HACKERS] Incrementally Updated Backup |