On 11/12/2012 10:44 AM, Craig Ringer wrote: > That'll make it hard for VACUUM, hint-bit setting, etc to > opportunistically checksum pages whenever they're doing a page write anyway.
It *is* a hard problem, yes. And the single bit doesn't really solve it. So I'm arguing against opportunistically checksumming in general. Who needs that anyway? > Is it absurd to suggest using another bitmap, like the FSM or visibility > map, to store information on page checksumming while checksumming is > enabled but incomplete? Not absurd. But arguably inefficient, because that bitmap may well become a bottleneck itself. Plus there's the problem of making sure those pages are safe against corruptions, so you'd need to checksum the checksum bitmap... doesn't sound like a nice solution to me. This has certainly been discussed before. Regards Markus Wanner -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
