On Thu, Oct 6, 2016 at 5:56 AM, Simon Riggs <si...@2ndquadrant.com> wrote: > Just to point out that I've actually written this approach already. > The patch is available, Autonomous Subtransactions. > We discussed it in Ottawa and it was rejected. (I thought Robert was > there, but Serge and Tom definitely were).
Where is the patch? > See other posts in this thread by Serge and Craig to explain why. I don't think the posts on Craig and Serge explain why that approach was rejected or would be a bad idea. > We have various approaches... summarised in chronological order of > their suggestion > > 1. Use additional PGXACTs - rejected because it wouldn't provide enough room Of course, a background worker uses a PGXACT too and a lot more, so if you think extra PGXACTs are bad, you should *really* think background workers are bad. > 2. Use Autonomous SubTransactions - rejected because the semantics are > different to what we might expect from ATs In what way? I think the questions of how you implement it and what the semantics are are largely orthogonal questions. To which proposal is this referring? > 3. Use background transactions (this thread) Sure. > 4. Use pause and resume so we don't use up too many PGXACTs I don't know what "pause and resume" means. > * The labelling "Autonomous Transaction" is a simple coat of paint, > which can easily be transferred to a better implementation if one > comes. If one doesn't then its better to have something than nothing. > So I suggest we commit Background Transactions first and then in a > fairly thin commit, implement Autonomous Transactions on top of it for > now and if we get a better one, switch it over. I think we should implement background transactions and call them background transactions. That allows us to expose additional functionality which is useful, like the ability to kick something off and check back later for the results. There's no reason to call it background transactions and also call it autonomous transactions: one feature doesn't need two names. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers