May well be, though databases are very "sticky" so it would be a very long
migration timeline. There could be a migration path - "compact" a TDB1
database into a TDB2 area. Such an import-copy would work for any dataset,
and combination of files, making it a data loader tool.
I can imagine a faster compaction specific to TDB2 that is index-by-index,
but does not touch nodes, as an intermediate compaction - something I
haven't tried at all. Applying it index-by-index would break up the length
of time the system is in maintenance. The simple, and easy to get working
reliably, quad-copy-compaction as the first version of the process has a
lot going for it.
Andy
On 8 September 2017 at 19:18, Adam Soroka <aj...@apache.org> wrote:
> Just catching up.
>
> Sounds great, Andy, and thanks! +1
>
> One question-- as our resident expert on both TDB1 and TDB2 (:grin:) are
> you expecting that TDB2 would eventually replace TDB1 fully and we would
> gracefully move TDB1 our of the core in the same way as, for example,
> Fuseki1 or SDB? It sounds to me like there would be no reason not too, as
> TDB2 matures and becomes stable and widely supported.
>
>
> ajs6f
>
> On 2017-09-08 14:13, Andy Seaborne <a...@apache.org> wrote:
> > To add it to Fuseki.war is (= should be) a matter of adding the
> dependency:
> >
> > <dependency>
> > <groupId>org.seaborne.mantis</groupId>
> > <artifactId>tdb2</artifactId>
> > <version>0.3.0</version>
> > </dependency>
> >
> > It does not need to do anything with jena-fuseki-core (that depends on
> > TDB1) nor appear in the UI so no changes needed. System initialization is
> > by Jena's use of ServiceLoader. (I haven't tried - I'm on a chromebook
> > ATM). The standalone server is a copy of the Jena one with the dependency
> > added.
> >
> > I don't what the size change is - 750K-1M.
> >
> > If there is something else happening, do let me know.
> >
> > Andy
> >
> >
> > On 7 September 2017 at 14:43, Chris Tomlinson <
> chris.j.tomlin...@gmail.com>
> > wrote:
> >
> > > Hi,
> > >
> > > We very much would like to see TDB2 incorporated into Jena as an
> option,
> > > especially for the online compaction. I spent a bit of time trying to
> build
> > > a fuseki-tdb2-war module but it will be much easier if TDB2 is
> incorporated
> > > into Jena (we deploy fuseki as war into tomcat rather than the
> > > fuseki-tbd2-server approach).
> > >
> > > Thanks,
> > > Chris
> > >
> > > > On Sep 4, 2017, at 5:27 PM, Andy Seaborne <a...@apache.org> wrote:
> > > >
> > > > I'd like to offer TDB2 as a contribution to Apache Jena.
> > > >
> > > > It is by no means "finished" (is anything software ever finished?)
> but
> > > it is sufficiently there to talk about and kick the tyres; I'll send
> notes
> > > about the technical state of TDB2 separately in a moment.
> > > >
> > > > * It adds project overhead. The build is only a couple of minutes,
> > > including upload time, (a lot of testing is done with in-memory
> databases,
> > > like TDB1, which makes setup and teardown of tests much faster).
> However,
> > > more stuff in the codebase is still more to get right for a release.
> > > >
> > > > * Support: while TDB2 works, it is unproven and rough round the edges
> > > (unclear errors message, stacktraces rather than meaningful messages
> etc)
> > > and questions/tickets may be quite hard to respond to (complex
> situations;
> > > no track record of what's gone wrong before). Testing on MS Windows or
> > > macOS has not been done.
> > > >
> > > > * Integration: It is not stable enough to be used in mainstream
> Fuseki2
> > > as the default persistent database. I see this as happening gradually.
> > > There is a Fuseki+TDB2 jar built at the moment but you have to use
> > > configuration files to setup the database.
> > > >
> > > > https://github.com/afs/mantis/blob/master/use-fuseki-tdb2.md
> > > >
> > > > * Initial status: I suggest we label it "incoming" or some such - it
> > > > would not hold up a release for example, and not everything might be
> > > fixed at the point of a Jena release. It shouldn't stop the main code
> set
> > > that users rely on getting out in the usual cycle.
> > > >
> > > > * Legal issues: the code has always been under the Apache License
> > > (original work was done as part of grant from the UK gov which required
> > > open source deliverables) but it would be simpler and cleaner for, e.g.
> > > moving or fixing copyright/licence notices around, for there to be
> software
> > > grants. The two parties involved are myself and Epimorphics Ltd. Both
> > > parties are willing to submit the paperwork.
> > > >
> > > > * A project vote. This is a new set of modules so a formal, explicit
> > > vote seems worthwhile.
> > > >
> > > > Thoughts, concerns, questions?
> > > >
> > > > Andy
> > > >
> > > > The code:
> > > > https://github.com/afs/mantis
> > > > (I can clean this up before integration as to what we agree on, so
> that
> > > there is less noise and churn later).
> > > >
> > > > Builds:
> > > > org.seaborne.mantis:tdb2
> > > > org.seaborne.mantis:fuseki-tdb2-server
> > > >
> > >
> > >
> >
>
