Re: subtransactions -- storage manager
От | Simon Riggs |
---|---|
Тема | Re: subtransactions -- storage manager |
Дата | |
Msg-id | 1083308441.3100.331.camel@stromboli обсуждение исходный текст |
Ответ на | Re: subtransactions -- storage manager (Bruce Momjian <pgman@candle.pha.pa.us>) |
Ответы |
Re: subtransactions -- storage manager
|
Список | pgsql-patches |
On Fri, 2004-04-30 at 01:02, Bruce Momjian wrote: > Simon Riggs wrote: > > On Sun, 2004-04-25 at 19:06, Alvaro Herrera wrote: > > > Hackers, > > > > > > This patch adds subtransaction support into the storage manager. Files > > > created or dropped inside a subtransaction are correctly dealt with at > > > subtransaction commit or abort. > > > > > - pg_clog/pg_subtrans. Need a solution. > > > > > > > > > PS: somehow I managed to get tired of the phrase "nested transactions" > > > and I'm using the term "subtransactions" instead. In my head they are > > > the same thing ... > > > > Impressive. > > > > As you're aware, our current work overlaps. > > pg_clog doesn't seem like the place to record subtransactions, though > > maybe it is... could we not give subtransactions a txnid just as with > > flat transactions? That way we can record everything in pg_clog AND > > recovery will work without further modification - as long as the failure > > of a top level transaction causes failure of every subtransaction EVEN > > if the subtrans originally committed. > > The problem is we have to atomically mark multiple transactions as > committed/aborted in pg_clog. Each subtransaction does get its own xid, > it is just that pg_subtrans maps each xid to is parent xid for use in > atomically marking the xids as committed/aborted. > > Recovery via xlog should be fine. > Phewww! > > If you add pg_subtrans, you will need to make recovery work all over > > again...really, you don't want to be doing that, do you? > > > > I also have other questions.... > > Forgive my lack of attention: I want SAVEPOINTs, not subtransactions... > > how do we do those? > > Savepoints are basically just a BEGIN at the save point, and a ROLLBACK > to get you back to the saved spot. It is just window-dressing on top of > nested transactions. > OK, but is anybody working on the window dressing bit, so that we have ANSI compliant commands? Best Regards, Simon
В списке pgsql-patches по дате отправления: