Hi David, Am Freitag, den 23.03.2018, 10:54 -0400 schrieb David Steele: > On 3/23/18 5:36 AM, Michael Banck wrote: > > Am Donnerstag, den 22.03.2018, 12:22 -0400 schrieb David Steele: > > > > > > + if (phdr->pd_checksum != checksum) > > > > > > I've attached a patch that adds basic retry functionality. It's not > > > terrible efficient since it rereads the entire buffer for any block > > > error. A better way is to keep a bitmap for each block in the buffer, > > > then on retry compare bitmaps. If the block is still bad, report it. > > > If the block was corrected moved on. If a block was good before but is > > > bad on retry it can be ignored. > > > > I have to admit I find it a bit convoluted and non-obvious on first > > reading, but I'll try to check it out some more. > > Yeah, I think I was influenced too much by how pgBackRest does things, > which doesn't work as well here. Attached is a simpler version.
This looks much cleaner to me, yeah. > > I agree that major corruption could make the whole output blow up but I > > would prefer to keep this feature simple for now, which implies possibly > > printing out a lot of WARNING or maybe just stopping after the first > > one (or first few, dunno). > > In my experience actual block errors are relatively rare, so there > aren't likely to be more than a few in a file. More common are > overwritten or transposed files, rogue files, etc. These produce a lot > of output. > > Maybe stop after five? I'm on board with this, but I have the feeling that this is not a very common pattern in Postgres, or might not be project style at all. I can't remember even seen an error message like that. Anybody know whether we're doing this in a similar fashion elsewhere? Michael -- Michael Banck Projektleiter / Senior Berater Tel.: +49 2166 9901-171 Fax: +49 2166 9901-100 Email: michael.ba...@credativ.de credativ GmbH, HRB Mönchengladbach 12080 USt-ID-Nummer: DE204566209 Trompeterallee 108, 41189 Mönchengladbach Geschäftsführung: Dr. Michael Meskes, Jörg Folz, Sascha Heuer
