On Wed, Apr 29, 2020 at 12:30 PM Mark Dilger <mark.dil...@enterprisedb.com> wrote: > Version 4 of this patch now includes boolean options skip_all_frozen and > skip_all_visible.
I'm not sure sure, but maybe there should just be one argument with three possible values, because skip_all_frozen = true and skip_all_visible = false seems nonsensical. On the other hand, if we used a text argument with three possible values, I'm not sure what we'd call the argument or what strings we'd use as the values. Also, what do people -- either those who have already responded, or others -- think about the idea of putting a command-line tool around this? I know that there were some rumblings about this in respect to pg_verifybackup, but I think a pg_amcheck binary would be well-received. It could do some interesting things, too. For instance, it could query pg_class for a list of relations that amcheck would know how to check, and then issue a separate query for each relation, which would avoid holding a snapshot or heavyweight locks across the whole operation. It could do parallelism across relations by opening multiple connections, or even within a single relation if -- as I think would be a good idea -- we extended heapcheck to take a range of block numbers after the style of pg_prewarm. Apart from allowing for client-driven parallelism, accepting block number ranges would have the advantage -- IMHO pretty significant -- of making it far easier to use this on a relation where some blocks are entirely unreadable. You could specify ranges to check out the remaining blocks. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
