Re: [HACKERS] Full page writes improvement, code update

On Fri, 2007-03-30 at 11:27 +0100, Richard Huxton wrote:

> Is that always true? Could the backup not pick up a partially-written
> page? Assuming it's being written to as the backup is in progress. (We
> are talking about when disk blocks are smaller than PG blocks here, so
> can't guarantee an atomic write for a PG block?)

Any page written during a backup has a backup block that would not be
removable by Koichi's tool, so yes, you'd still be safe.

i.e. between pg_start_backup() and pg_stop_backup() we always use full
page writes, even if you are running in full_page_writes=off mode.

--
  Simon Riggs
  EnterpriseDB   http://www.enterprisedb.com