> > I believe the idea was to make this as non-invasive as possible. And > it would be really nice if this could be enabled without a dump/ > reload (maybe the upgrade stuff would make this possible?) > --
It's all about the probability of a duplicate check being generated. If you use a 32 bit checksum, then you have a theoretical probability of 1 in 4 billion that a corrupt block will be missed (probably much lower depending on your algorithm). If you use a short, then a 1 in 65 thousand probability. If you use an 8 bit number, then 1 in 256. Why am I going on? Well, if there are any spare bits in a block header, they could be used for the check value. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
