On Thu, Jan 20, 2022 at 6:06 AM Bossart, Nathan <bossa...@amazon.com> wrote: > > On 1/3/22, 5:52 PM, "Kyotaro Horiguchi" <horikyota....@gmail.com> wrote: > > It seems to me "LSN" or just "location" is more confusing or > > mysterious than "REDO LSN" for the average user. If we want to avoid > > being technically too detailed, we would use just "start LSN=%X/%X, > > end LSN=%X/%X". And it is equivalent to "WAL range=[%X/%X, %X/%X]".. > > My first instinct was that this should stay aligned with > pg_controldata, but that would mean using "location=%X/%X, REDO > location=%X/%X," which doesn't seem terribly descriptive. IIUC the > "checkpoint location" is the LSN of the WAL record for the checkpoint, > and the "checkpoint's REDO location" is the LSN where checkpoint > creation began (i.e., what you must retain for crash recovery). My > vote is for "start=%X/%X, end=%X/%X."
I'm still not clear how the REDO location can be treated as a start LSN? Can someone throw some light one what this checkpoint's REDO location is? Regards, Bharath Rupireddy.
