On Dec30, 2010, at 13:31 , Joachim Wieland wrote: > We return snapshot information as a chunk of data to the client. At > the same time however, we set a checksum in shared memory to protect > against modification of the snapshot. A publishing backend can revoke > its snapshot by deleting the checksum and a backend that is asked to > install a snapshot can verify that the snapshot is correct and current > by calculating the checksum and comparing it with the one in shared > memory.
We'd still have to stream these checksums to the standbys though, or would they be exempt from the checksum checks? I still wonder whether these checks are worth the complexity. I believe we'd only allow snapshot modifications for read-only queries anyway, so what point is there in preventing clients from setting broken snapshots? best regards, Florian Pflug -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
