On Wed, May 4, 2016 at 6:28 PM, Andres Freund <and...@anarazel.de> wrote: > On 2016-05-04 18:22:27 -0400, Robert Haas wrote: >> On Wed, May 4, 2016 at 6:06 PM, Andres Freund <and...@anarazel.de> wrote: >> >> Some of the proposals involve fairly small tweaks to call >> >> MaintainOldSnapshotTimeMapping() from elsewhere or only when >> >> something changes (like crossing a minute boundary or seeing that a >> >> new TransactionId has been assigned). If you can disentangle those >> >> ideas, it might not look so bad. >> > >> > Yea, if we can do that, I'm ok. I'm doubtful about releasing with the >> > current state, even leaving performance aside, since fixing this will >> > result in somewhat changed semantics, and I'm doubtful about significant >> > development at this point of the release process. If it comes down to >> > either one of those I'm clearly in favor of the latter. >> >> How would the semantics change? > > Right now the time for computing the snapshot is relevant, if > maintenance of xids is moved, it'll likely be tied to the time xids are > assigned. That seems perfectly alright, but it'll change behaviour.
Not following. >> So, I was worried about this, too. But I think there is an >> overwhelming consensus on pgsql-release that getting a beta out early >> trumps all, and that if that results in somewhat more post-beta1 >> change than we've traditionally had, so be it. > > *If* that's the policy - cool! I just don't want to see the issue > not being fixed due to only wanting conservative changes. And the > discussion around fixing spinlock related issues in the patch certainly > made me think the RMT aimed to be conservative. Understand that I am conveying what I understand the sentiment of the community to be, not guaranteeing any specific outcome. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
