Amit Kapila <amit.kap...@huawei.com> writes: >> The reason I'm concerned about selecting a next-LSN that's certainly beyond >> every LSN in the database is that not doing >> so could result in introducing further corruption, which would be entirely >> avoidable with more care in choosing the >> next-LSN.
> The further corruption can only be possible when we replay some wrong > WAL by selecting wrong LSN. No, this is mistaken. Pages in the database that have LSN ahead of where the server thinks the end of WAL is cause lots of problems unrelated to replay; for example, inability to complete a checkpoint. That might not directly lead to additional corruption, but consider the case where such a page gets further modified, and the server decides it doesn't need to create a full-page image because the LSN is ahead of where the last checkpoint was. A crash or two later, you have new problems. (Admittedly, once you've run pg_resetxlog you're best advised to just be trying to dump what you've got, and not modify it more. But sometimes you have to hack the data just to get pg_dump to complete.) regards, tom lane -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers