On 3/3/17 2:43 AM, Tsunakawa, Takayuki wrote: > From: Tom Lane [mailto:t...@sss.pgh.pa.us] >> 1. The argument for this is mostly, if not entirely, "application >> compatibility". But it won't succeed at providing that if every BEGIN has >> to be spelled differently than it would be on other DBMSes. >> Therefore there is going to be enormous pressure to allow enabling the >> feature through a GUC, or some other environment-level way, and as soon >> as we do that we've lost. > > I thought so, too. I believe people who want to migrate from other DBMSs > would set the GUC in postgresql.conf, or with ALTER DATABASE/USER just for > applications which are difficult to modify. > >> 2. The proposed feature would affect the internal operation of PL functions, >> so that those would need to become bulletproof against being invoked in >> either operating environment. Likewise, all sorts of intermediate tools >> like connection poolers would no doubt be broken if they don't know about >> this and support both modes. (We would have to start by fixing postgres_fdw >> and dblink, for instance.) > > Yes, I'm going to modify the PL's behavior. I'll also check the dblink and > postgres_fdw as well. In addition, I'll have a quick look at the code of > pgpool-II and pgBouncer to see how they depend on the transaction state. > I'll run the regression tests of contribs, pgpool-II and pgBouncer with > default_transaction_rollback_scope set to 'statement'. > > But I don't see how badly the statement-level rollback affects those features > other than PL. I think the only relevant thing to those client-side programs > is whether the transaction is still running, which is returned with > ReadyForQuery. Both of statement-level rollback and the traditional behavior > leave the transaction running when an SQL statement fails. Server-side > autocommit differs in that respect.
Whatever the merits of this patch, it's a pretty major behavioral change with a large potential impact. Even if what is enumerated here is the full list (which I doubt), it's pretty big. Given that this landed on March 28 with no discussion beforehand, I recommend that we immediately move this patch to the 2017-07 CF. -- -David da...@pgmasters.net -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
