On Mon, Mar 6, 2023 at 1:26 PM Michael Paquier <mich...@paquier.xyz> wrote: > > On Sat, Mar 04, 2023 at 09:47:05AM +0530, Bharath Rupireddy wrote: > > Okay, here's a patch attached. > > Thanks. > > + * When source == XLOG_FROM_ANY, this function first searches for the segment > + * with a TLI in archive first, if not found, it searches in pg_wal. This > way, > + * if there is a WAL segment with same passed-in segno but different TLI > + * present in both the archive and pg_wal, it prefers the one with higher > TLI. > + * The reason for this is that if for example we try to do archive recovery > to > + * timeline 2, which branched off timeline 1, but the WAL for timeline 2 is > not > + * archived yet, we would replay past the timeline switch point on timeline 1 > + * using the archived WAL segment, before even looking timeline 2's WAL > + * segments in pg_wal. > > This is pretty much what the commit has mentioned. The first half > provides enough details, IMO.
IMO, mentioning the example from the commit message in the function comment makes things more clear - one doesn't have to go look for the commit message for that. -- Bharath Rupireddy PostgreSQL Contributors Team RDS Open Source Databases Amazon Web Services: https://aws.amazon.com
