On Tue, Aug 12, 2014 at 8:26 PM, Stephen Frost <sfr...@snowman.net> wrote: > * Claudio Freire (klaussfre...@gmail.com) wrote: >> I'm not talking about malicious attacks, with big enough data sets, >> checksum collisions are much more likely to happen than with smaller >> ones, and incremental backups are supposed to work for the big sets. > > This is an issue when you're talking about de-duplication, not when > you're talking about testing if two files are the same or not for > incremental backup purposes. The size of the overall data set in this > case is not relevant as you're only ever looking at the same (at most > 1G) specific file in the PostgreSQL data directory. Were you able to > actually produce a file with a colliding checksum as an existing PG > file, the chance that you'd be able to construct one which *also* has > a valid page layout sufficient that it wouldn't be obviously massivly > corrupted is very quickly approaching zero.
True, but only with a strong hash, not an adler32 or something like that. -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
