On Mon, Jul 11, 2022 at 3:34 PM Andres Freund <andres@anarazel.de> wrote:
> Seems pretty simple to do. Have write_relmapper_file() write to a .tmp file
> first (likely adding O_TRUNC to flags), use durable_rename() to rename it into
> place. The tempfile should probably be written out before the XLogInsert(),
> the durable_rename() after, although I think it'd also be correct to more
> closely approximate the current sequence.
Something like this?
I chose not to use durable_rename() here, because that allowed me to
do more of the work before starting the critical section, and it's
probably slightly more efficient this way, too. That could be changed,
though, if you really want to stick with durable_rename().
I haven't done anything about actually making the file variable-length
here, either, which I think is what we would want to do. If this seems
more or less all right, I can work on that next.
--
Robert Haas
EDB: http://www.enterprisedb.com