On Thu, 2011-07-28 at 18:05 +0200, Hannu Krosing wrote: > But it is also possible, that you can get logically consistent snapshots > by protecting only some ops. for example, if you protect only insert and > get snapshot, then the worst that can happen is that you get a snapshot > that is a few commits older than what youd get with full locking and it > may well be ok for all real uses.
Thinking more of it, we should lock commit/remove_txid and get_snapshot having a few more running backends does not make a difference, but seeing commits in wrong order may. this will cause contention between commit and get_snapshot, but hopefully less than current ProcArray manipulation, as there is just one simple C array to lock and copy. -- ------- Hannu Krosing PostgreSQL Infinite Scalability and Performance Consultant PG Admin Book: http://www.2ndQuadrant.com/books/ -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
