On Sat, Aug 18, 2012 at 1:34 AM, Craig Ringer <ring...@ringerc.id.au> wrote: > On 08/07/2012 09:45 PM, Kevin Grittner wrote: >> >> I also think it's a problem that one can get through the entire >> "Concurrency Control" chapter (mvcc.sgml) without a clue that >> sequences aren't transactional. I think maybe a mention in the >> Introduction section of that chapter with a <ref> would be >> appropriate. > > > How about this? Is it accurate to suggest that sequences behave as if they > were always in "dirty read" isolation?
I don't think so. I would think that a dirty read would allow unresolved data to be visible, but upon rollback of the other transaction would stop seeing the "dirty" data. That doesn't describe sequences. A better explanation is that sequence advancement is autonomously committed. > Or would you instead say that > "changes made to a sequence are immediately visible to all other > transactions" ? Yes, that sounds better. Cheers, Jeff -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
