Re: Problem with PITR recovery

On Mon, 2005-04-18 at 19:21 -0400, Tom Lane wrote:
> Simon Riggs <simon@2ndquadrant.com> writes:
> > The wal file could be truncated after the log switch record, though I'd
> > want to make sure that didn't cause other problems.
> 
> Which it would: that would break WAL file recycling.

Yeh, there's just too many references to the file length for comfort.

> > That would be initiated through a single function pg_walfile_switch()
> > which would be called from 
> > 1) pg_stop_backup()
> > 2) by user command
> > 3) at a specified timeout within archiver (already built in)
> 
> I would really, really, like NOT to have a user command for this.
> (If pg_stop_backup does it, that already provides an out for anyone
> who thinks they need to invoke it manually.)

Actually, me too. Never saw the need for the Oracle command myself.

> > A shutdown checkpoint would also have the same effect as an
> > XLOG_FILE_SWITCH instruction, so that the archiver would be able to copy
> > away the file.
> 
> The archiver is stopped before we do the shutdown, no?

Currently, the bgwriter issues the Shutdown checkpoint and the archiver
is always stopped after the bgwriter has issued the checkpoint and quit.
It should be possible to send archiver a signal to attempt any remaining
archiving before shutdown.

Of course, this behaviour would only be initiated when
XLogArchivingActive() is true, since it makes no sense otherwise.

> > I'd suggest this as a backpatch for 8.0.x, when completed.
> 
> Not a chance --- it's a new feature, not a bug fix, and has substantial
> risk of breaking things.

No problem for me personally; I only request it, according to users
wishes.

Best Regards, Simon Riggs