Hello Sawada-San
On Monday, December 28, 2020 2:29 PM Masahiko Sawada <sawada.m...@gmail.com> wrote: > On Thu, Dec 3, 2020 at 12:14 PM osumi.takami...@fujitsu.com > <osumi.takami...@fujitsu.com> wrote: > > > > I've made a new patch v05 that took in comments to filter out WALs > > more strictly and addressed some minor fixes that were discussed > > within past few days. > > Also, I changed the documentations, considering those modifications. > > From a backup management tool perspective, how can they detect that > wal_level has been changed to ‘none' (and back to the normal)? IIUC once > we changed wal_level to none, old backups that are taken before setting to > ‘none’ can be used only for restoring the database to the point before the > LSN where setting 'wal_level = none'. The users can neither restore the > database to any points in the term of 'wal_level = none' nor use an old backup > to restore the database to the point after LSN where setting 'wal_level = > none’. I think we might need to provide a way to detect the changes other > than reading XLOG_PARAMETER_CHANGE. In the past, we discussed the aspect of backup management tool in [1] and concluded that this should be another patch separated from this thread because to compare the wal_level changes between snapshots applies to wal_level = minimal, too. Please have a look at the "second idea" in the e-mail in the [1] and responses to it. [1] - https://www.postgresql.org/message-id/OSBPR01MB4888B34B81A6E0DD46B5D063EDE00%40OSBPR01MB4888.jpnprd01.prod.outlook.com Best Regards, Takamichi Osumi