Bruce Momjian <pgman ( at ) candle ( dot ) pha ( dot ) pa ( dot ) us> writes: > > I am thinking we should throw an error on pg_start_backup() and > > pg_stop_backup if full_page_writes is off. > > No, we'll just change the test in xlog.c so that fullPageWrites is > ignored if XLogArchivingActive. > > > Seems archive_command and > > full_page_writes can still be used if we are not in the process of doing > > a file system backup. > > Think harder: we are only safe if the first write to a given page after > it's mis-copied by the archiver is a full page write. The requirement > therefore continues after pg_stop_backup. Unless you want to add > infrastructure to keep track for *every page* in the DB of whether it's > been fully written since the last backup?
I am confused. Since we checkpoint during pg_start_backup(), isn't any write to a file while the tar backup is going on going to be a full page write? And once we pg_stop_backup(), do we need full page writes? -- Bruce Momjian http://candle.pha.pa.us EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. + ---------------------------(end of broadcast)--------------------------- TIP 4: Have you searched our list archives? http://archives.postgresql.org
