Does anyone know how MySQL or PostgreSQL work with checkpoints? Do they
support it in a similar way?
On Mon, Nov 7, 2016 at 5:58 AM, Yakov Zhdanov <yzhda...@apache.org> wrote:
> Alex, I think we should put consecutive checkpoints to stack thus your
> example should be illegal and should result to exception. And we will throw
> exception on rollback to CP if CP is not defined.
>
> --Yakov
>
> 2016-11-07 14:23 GMT+03:00 Alexey Goncharuk <alexey.goncha...@gmail.com>:
>
> > We also should define savepoint behavior and API rules for each of the
> > transaction concurrency and isolation types.
> >
> > * Should rollbackToSavepoint() always release locks or clear saved
> > optimistic versions?
> > * Are forward-rollbacks allowed, e.g.
> >
> > try (Transaction tx = ignite.transactions().txStart()) {
> > c.put(1, 1);
> >
> > tx.savepoint("sp1");
> >
> > c.put(2, 2);
> >
> > tx.savepoint("sp2")
> >
> > c.put(3, 3);
> >
> > tx.rollbackToSavepoint("sp1");
> >
> > c.put(4, 4);
> >
> > tx.rollbackToSavepoint("sp2"); // Is this allowed?
> >
> > tx.commit();
> > }
> >
> >
> > 2016-11-07 13:47 GMT+03:00 Sergey Kozlov <skoz...@gridgain.com>:
> >
> > > Hi, Yakov
> > >
> > > I suppose it's very very handy feature.
> > > My two cents are following:
> > > - number of savepoints may be more than one per transaction
> > > - what's about RELEASE SAVEPOINT statement?
> > >
> > >
> > > On Mon, Nov 7, 2016 at 11:24 AM, Yakov Zhdanov <yzhda...@apache.org>
> > > wrote:
> > >
> > > > Guys,
> > > >
> > > > Let's think of implementing savepoints for Ignite transactions. For
> me,
> > > > this is not too hard to do.
> > > >
> > > > Having "savepoints" seems to be pretty handy. Please consider the
> > > following
> > > > snippet.
> > > >
> > > > ignite.transactions.;
> > > > INSERT INTO table1 VALUES (1);
> > > > SAVEPOINT my_savepoint;
> > > > INSERT INTO table1 VALUES (2);
> > > > ROLLBACK TO SAVEPOINT my_savepoint;
> > > > INSERT INTO table1 VALUES (3);
> > > > COMMIT;
> > > >
> > > > Which should result in values 1 and 3 inserted to table1.
> > > >
> > > > In Ignite, I think, it would be like the following (preserving the
> > same
> > > > behavior as above).
> > > >
> > > > Ignite ignite = ....;
> > > > IgniteCache<Integer, Integer> c = ....;
> > > >
> > > > try (Transaction tx = ignite.transactions().txStart()) {
> > > > c.put(1, 1);
> > > >
> > > > tx.savepoint("mysavepoint");
> > > >
> > > > c.put(2, 2);
> > > >
> > > > tx.rollbackToSavepoint("mysavepoint");
> > > >
> > > > c.put(3, 3);
> > > >
> > > > tx.commit();
> > > > }
> > > >
> > > > As far as implementation complexity I would give 2 weeks ballpark.
> > > >
> > > > 5 days - API design and implementation for different types of
> > > transactions
> > > > - savepoint implementation for local transaction objects
> > > > - rollback implementation for different types of transactions - drain
> > > local
> > > > tx buffers, release remote locks for pessimistic transactions, etc.
> > > >
> > > > 5 days - testing, benchmarking, fixing issues.
> > > >
> > > > Please leave your comments here. I will file a ticket after we
> discuss
> > > this
> > > > and put our summary to it.
> > > >
> > > > Thanks!
> > > >
> > > > --Yakov
> > > >
> > >
> > >
> > >
> > > --
> > > Sergey Kozlov
> > > GridGain Systems
> > > www.gridgain.com
> > >
> >
>
