Re: Support for 2-Phase Commit protocol
От | Alexander Staubo |
---|---|
Тема | Re: Support for 2-Phase Commit protocol |
Дата | |
Msg-id | 406882D4.6000403@byzantine.no обсуждение исходный текст |
Ответ на | Re: Support for 2-Phase Commit protocol ("Freddy Villalba Arias" <fvillalba@madrid.bilbomatica.es>) |
Список | pgsql-jdbc |
on 2004-03-29 19:43 Freddy Villalba Arias wrote: > I'm currently envolved in a Project requiring v7.4 (7.4.2?). I won't > be using distributed transaction, but transactions that span multiple > objects (all of them on the same JVM). Therefore, as I understood it > from reading the JTA spec, I should not need to use the XA "objects" > (XAConnection...) but just "plain JDBC"'s ones (Connection, > Statement...). What do you mean by multiple objects? Sounds like you have multiple transactions on a single back end that all need to complete atomically -- more related to nested transactions and savepoints than to two-phase commits. > Then, the following question arises: does the fact that 2-Phase commit > isn't yet supported imply that I cannot use JTA? It's been a while since I read the JTA spec, but even if the transaction manager did not require XA support from the driver, it still would not be able to glue your transactions together using a two-phase commit, which is what you want. So the TM would commit each transaction individually, but it would not be able to roll them back in the case of mid-point failure. The point of the XA interfaces is to encapsulate the two-phase protocol, allowing local transactions to be prepared before they are committed. Without the XA support, JTA is basically a standard interface to a transaction manager and X/Open-style transaction semantics. I assume Bruce is talking either about this patch: http://archives.postgresql.org/pgsql-patches/2003-10/msg00273.php or this work: http://snaga.org/pgsql/ Alexander. on 2004-03-29 19:43 Freddy Villalba Arias wrote: > I'm currently envolved in a Project requiring v7.4 (7.4.2?). I won't > be using distributed transaction, but transactions that span multiple > objects (all of them on the same JVM). Therefore, as I understood it > from reading the JTA spec, I should not need to use the XA "objects" > (XAConnection...) but just "plain JDBC"'s ones (Connection, > Statement...). > > Then, the following question arises: does the fact that 2-Phase commit > isn't yet supported imply that I cannot use JTA? Are these to issues > unrelated? > > I'll look forward for your feedback. > > -----Mensaje original----- > De: Bruce Momjian [mailto:pgman@candle.pha.pa.us] > Enviado el: lunes, 29 de marzo de 2004 18:36 > Para: Alexander Staubo > CC: Freddy Villalba Arias; PostgreSQL JDBC Mailing List > Asunto: Re: [JDBC] Support for 2-Phase Commit protocol > > > Someone has a 2-phase commit patch and we are looking to get it into > 7.5. > > > ------------------------------------------------------------------------ > --- > > Alexander Staubo wrote: > >>This is on the PostgreSQL todo list: >> >> http://developer.postgresql.org/todo.php >> >>However, as far as I know it's not something people are working >>actively on, or at least not to the extent that we will see a release >>in the near term. I would like to be wrong, though. >> >>Seeing as this is a server issue and not specifically a JDBC issue, >>the pgsql-hackers list is probably the place to ask about the >>development status of future features. >> >>To my knowledge, Firebird (http://www.firebirdsql.org/) is the only >>open-source database that supports two-phase commits; its JDBC driver >>comes with JTA support. You may have better luck with that. Firebird >>is itself a decent database, but is going to feel like a step back >>into the '80s once you've gotten used to PostgreSQL's sleek, modern >>facilities [*]. >> >>[*] Variable-length "text" data type that does not need a pre-declared > > >>size, virtually unlimited row sizes, online alter/drop/rename for >>tables/columns/etc., ability to index fields declared as >250 chars >>long, SQL shell with proper readline support, intelligible error >>messages, mature documentation, I could go on. >> >>Alexander. >> >>on 2004-03-29 17:19 Freddy Villalba Arias wrote: >> >> >>>Hi everybody, >>> >>> >>> >>>I forgot to include this other question (also urgent, sorry if I?m >>>stressing you up): does anybody know what is PostgreSQL?s current > > status > >>>regarding ?Two Phase Commit Protocol Support?? >>> >>> >>> >>>Again, thanx. >>> >>> >>> >>>Regards, >>> >>>Freddy. >>> >> >> >>---------------------------(end of > > broadcast)--------------------------- > >>TIP 6: Have you searched our list archives? >> >> http://archives.postgresql.org >> > >
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