Hello Kyotaro,
On Tue, 30 Aug 2022 at 09:51, Kyotaro Horiguchi <horikyota....@gmail.com> wrote: > > > And as I said in a mail I sent just before, the patch looks too > complex. How about just comparing WAL file name aginst the last > common checkpoint's tli and lsn? We can tell filemap.c about the last > checkpoint and decide_file_action can compare the file name with it. > > It is sufficient to preserve WAL files if tli matches and the segment > number of the WAL file is equal to or later than the checkpoint > location. > What if the last common checkpoint was on a previous timeline? I.e., standby was promoted to primary, the timeline changed from 1 to 2, and after that the node crashed _before_ the CHECKPOINT after promote has finished. The next node will advance the timeline from 2 to 3. In this case, the last common checkpoint will be on timeline 1, and the check becomes more complex because we will have to consider both timelines, 1 and 2. Also, we need to take into account the divergency LSN. Files after it are not required. Regards, -- Alexander Kukushkin
