On 30 December 2012 02:45, Daniel Farina <dan...@heroku.com> wrote: > As I recall, the gist of this objection had to do with a false sense > of stability of the hash value, and the desire to enforce the ability > to alter it. Here's an option: xor the hash value with the > 'statistics session id', so it's *known* to be unstable between > sessions. That gets you continuity in the common case and sound > deprecation in the less-common cases (crashes, format upgrades, stat > resetting).
Hmm. I like the idea, but a concern there would be that you'd introduce additional scope for collisions in the third-party utility building time-series data from snapshots. I currently put the probability of a collision within pg_stat_statements as 1% in the event of a pg_stat_statements.max of 10,000. -- Peter Geoghegan http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training and Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
