Robert Haas escribió: > A broader complaint I have with this patch is that it almost but > not-quite solves a problem I've had a few times in the past: namely, > searching through the data directory for data blocks which have LSNs > in the future. This has come up a few times for me, and this tool > would make it easier, because I'd be able to run it and look through > the output to see which relations have high max-LSN values. However, > it wouldn't be quite enough, because it'd only tell me about the block > with the highest LSN in each file, whereas what I'd really want to > find is every block with an LSN greater than some threshold value. > Maybe I'm pushing the envelope too much by trying to fit that into the > framework of this patch, but I can't help thinking we're not going to > want both pg_computemaxlsn and pg_findlsnsaftersomethreshold that are > 95% the same code, so maybe we ought to rename the utility to > something slightly more generic than "pg_computemaxlsn".
Perhaps not coincidentally, I had a need to do this recently. Perhaps we should turn the utility into a generic tool to report existing LSNs, with options to 1) report only the highest one in a given file, 2) report only those that exceed some threshold. So maybe pg_reportlsn or pg_extractlsn. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
