Simon Riggs wrote:
On Tue, 2008-07-22 at 17:19 -0700, Martin Zaun wrote:
8. Unresolved question of implementing now/later a "cp" replacement


The patch implements what's been agreed.
I'm not rewriting "cp", for reasons already discussed.

Not a comment to you Martin, but it's fairly clear that I'm not
maintaining this correctly for Windows. I've never claimed to have
tested this on Windows, and only included Windows related items as
requested by others. I need to make it clear that I'm not going to
maintain it at all, for Windows. If others wish to report Windows issues
then they can suggest appropriate fixes and test them also.

Hmm. I just realized that replacing the "cp" command within pg_standby won't help at all. The problem is with the command that copies the files *to* the archivelocation that pg_standby polls, not with the copy pg_standby does from archivelocation to pg_xlog. And we don't have much control over that.

We really need a more reliable way of detecting that a file has been fully copied. One simple improvement would be to check the xlp_magic field of the last page, though it still wouldn't be bullet-proof.

Do the commands that preallocate the space keep the file exclusively locked during the copy? If they do, shouldn't we get an error in trying to run the restore copy command, and retry after the 1s sleep in RestoreWALFileForRecovery? Though if the archive location is a samba mount or something, I guess we can't rely on Windows-style exclusive locking.

--
  Heikki Linnakangas
  EnterpriseDB   http://www.enterprisedb.com

--
Sent via pgsql-patches mailing list (pgsql-patches@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-patches

Reply via email to