You could certainly use Jena to keep a repository of those kinds of metadata mappings and use it to help drive queries into either of the source databases (or to merge that data into a new database, which might or might not be RDF based). But what Jena doesn't give you is any specific tooling for doing the discovery process, as far as saying "EMP in DB1 is most likely the same thing as EMPLOYEE in DB2". That could be done, but it is orthogonal to whether or not you use Jena.
How you'd go about doing the that discovery (leaving aside the idea of doing it all by hand) is probably going to be non-deterministic and is probably close to an open research problem in the AI / Machine Learning realm. Phil This message optimized for indexing by NSA PRISM On Wed, Sep 7, 2016 at 2:57 PM, John A. Fereira <[email protected]> wrote: > > I am not exactly clear what Ravion is trying to do but wondered if D2R Map > might help > > https://sourceforge.net/projects/d2r-map/ > > > It would require setting up two D2R config files that each mapped one of > the database into a common RDF model > > > > > On 9/7/16, 2:39 PM, "Martynas Jusevičius" <[email protected]> wrote: > > >I think R2RML and GRDDL could be of interest to you: > >https://www.w3.org/TR/r2rml/ > >https://www.w3.org/TR/grddl/ > > > >On Wed, Sep 7, 2016 at 8:00 PM, ☼ R Nair (रविशंकर नायर) > ><[email protected]> wrote: > >> Agree, the question is whether an RDF can be created out of the data > from > >> multiple data sources and use it for semantic correlation. That would > turn > >> the world round. In my organization, there are at least a PB of data > lying > >> in disparate sources, untapped because , they are legacy and none knows > the > >> relationships until explored manually. If Jean is not, any suggestions > to > >> manage this? Thanks > >> > >> Best, Ravion > >> > >> On Sep 7, 2016 1:55 PM, "A. Soroka" <[email protected]> wrote: > >> > >> Jena is an RDF framework-- it's not really designed to integrate SQL > >> databases. Are you sure you are using the right product? Does your use > case > >> involve a good deal of RDF processing? > >> > >> --- > >> A. Soroka > >> The University of Virginia Library > >> > >>> On Sep 7, 2016, at 1:43 PM, ☼ R Nair (रविशंकर नायर) < > >> [email protected]> wrote: > >>> > >>> All, > >>> > >>> I am new to Jena. I would like to query two databases, mysql and > Oracle. > >>> Assume that there are similar columns in both. For example MYSQL > contains > >> a > >>> table EMP with ENAME column. Oracle contains, say, DEPT table with > >>> EMPLOYEENAME column. What are the steps if I want Jena to find out > ENAME > >> of > >>> MYSQL is same as EMPLOYEENAME column of Oracle, ( and so can be > joined). > >> Is > >>> this possible, at least to get an output saying both columns are > similar? > >>> If so, how, thanks and appreciate your help. > >>> > >>> Best, Ravion >
