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.
> 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.)
> 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?
> 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.
regards, tom lane