> > The probably useful next step would be to pass the current length to the > > archive_command, > > so it can write the filled part of the file without the need for a > > filter. > > I can see that helping a lot, but not by writing onto the file on disk. > If the file is nearly empty, that would be a lot of disk I/O which doesn't > need to happen.
I think you misunderstood what I meant. The actual archive command is constructed by expanding certain placeholders. I am suggesting to add such a placeholder for the size of the filled part of the log. A hypothetical example (note suggested %b placeholder for size in bytes): archive_command=dd if=%p of=/backup/WAL/%f bs=1 count=%b This allows to avoid unnecessary io for the backup of partially filled logs. Andreas ---------------------------(end of broadcast)--------------------------- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq