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Posted to users@jena.apache.org by "Dimov, Stefan" <st...@sap.com> on 2018/01/03 23:02:47 UTC

Re: Jena with RDBMS or alternative graph DB

Thanks Andy,

I wanna clarify my questions. 

In case we don’t use TDB, the alternative is already chosen (whether we like it or not). It’s a specific platform, that has both Graph and Relational DB that are very fast.

They both don’t have SPARQL adapters.

We want to avoid implementing SPARQL layers, so my question is: 

In which case I would have less efforts (NOT implementing SPARQL layer), Relational DB adapter or Graph DB adapter, or in both cases I will need to implement and maintain the SPARQL layer?

Regards,
Stefan



On 12/22/17, 4:41 PM, "Andy Seaborne" <an...@apache.org> wrote:

    
    
    On 23/12/17 00:15, Dimov, Stefan wrote:
    > Thanks Andy,
    > 
    > I didn’t quite understand this:
    > 
    > “1/ Use SPARQL (interface RDFConnection) to connect to a remote triple
    >      store.  SPARQL tripe stores are very good at implementing the standards.”
    > 
    > Does it mean that the graph DB I wanna use, should (out-of-the-box) support triples and SPARQL or this is the part that I should implement in order to use it with Jena?
    
    There are quiet a few SPARQL triple stores.  Choose and use.
    
    RDFConnection is part of the Jena codebase.
    
    > 
    > Can you, please, point me, to examples how to:
    > 	
    > 1. Implement SQL adapter
    
    See the code for jena-sdb. This component is "maintenance only".
    
    > 2. Implement usage of alternative graph DB
    
    Choose your SPARQL triplestore, download and use!
    
    SPARQL and it's protocols are standards. The tripe store can be any one 
    that implements the standards. In the SPARQL world, compliance levels 
    are high.
    
    > 
    > Happy holidays!
    > Stefan
    > 
    > 
    > On 12/21/17, 1:46 AM, "Andy Seaborne" <an...@apache.org> wrote:
    > 
    >      
    >      
    >      On 21/12/17 04:41, Dimov, Stefan wrote:
    >      > Hi all,
    >      >
    >      > Where can I find more detailed info on how can use Jena with:
    >      >
    >      >
    >      >    1.  RDBMS
    >      >       *   Does it support just any RDBMS?
    >      
    >      The supported databases are described in the documentation:
    >      
    >      https://jena.apache.org/documentation/sdb/databases_supported.html
    >      
    >      Note:
    >      [[
    >      Use of SDB for new applications is not recommended.
    >      This component is "maintenance only".
    >      TDB is faster, more scalable and better supported than SDB.
    >      ]]
    >      
    >      >       *   If not, and I want to use it with different (from the supported) RDMS what should I do?
    >      
    >      Do you need it to be an SQL database? (Someone was doing HAMA at one
    >      time but we didn't hear back from them).
    >      
    >      You have to write the SQL adapter - SQL syntax, especially for DDL, is
    >      quite variable.  There are various examples to start with.
    >      
    >      But SDB does not have the scale and speed of a native graph database.
    >      
    >      >    1.  Alternative (not TDB) graph DB
    >      >       *   Is it possible
    >      
    >      Yes.
    >      
    >      1/ Use SPARQL (interface RDFConnection) to connect to a remote triple
    >      store.  SPARQL tripe stores are very good at implementing the standards.
    >      
    >      2/ See if the store of your choice offers a Jena adapter.
    >      
    >           Andy
    >      
    >      >       *   If not, can it easily be done?
    >      >
    >      > Regards,
    >      > Stefan
    >      >
    >      
    > 
    


Re: Jena with RDBMS or alternative graph DB

Posted by "Dimov, Stefan" <st...@sap.com>.
Thanks Andy, I gotta dig deeper here … I guess …

S.

On 1/4/18, 2:05 PM, "Andy Seaborne" <an...@apache.org> wrote:

    Big question. Details matter when considering the amount of work so I 
    can only make general comments.
    
    What's the interface to the graph ending part?  The public blogs (from 
    2016/08) suggest its stored in a vertex table and an edge table held in 
    the column store. The "graph algorthms" part is opaque.
    
    Some snooping around says the current version has partial openCypher 
    support. Mapping to that, and using the property graphs for easy mapping 
    to/from SPARQL. Map the basic graph pattern to openCypther - or go to 
    those tables, that's jena-sdb.
    
    Oracle use Jena for their SPARQL - they plugin in at the basic graph 
    pattern (or at least that was the state when I last heard).
    
    Then the majority of SPARQL is Jena ARQ.
    
         Andy
    
    On 03/01/18 23:02, Dimov, Stefan wrote:
    > Thanks Andy,
    > 
    > I wanna clarify my questions.
    > 
    > In case we don’t use TDB, the alternative is already chosen (whether we like it or not). It’s a specific platform, that has both Graph and Relational DB that are very fast.
    > 
    > They both don’t have SPARQL adapters.
    > 
    > We want to avoid implementing SPARQL layers, so my question is:
    > 
    > In which case I would have less efforts (NOT implementing SPARQL layer), Relational DB adapter or Graph DB adapter, or in both cases I will need to implement and maintain the SPARQL layer?
    > 
    > Regards,
    > Stefan
    > 
    > 
    > 
    > On 12/22/17, 4:41 PM, "Andy Seaborne" <an...@apache.org> wrote:
    > 
    >      
    >      
    >      On 23/12/17 00:15, Dimov, Stefan wrote:
    >      > Thanks Andy,
    >      >
    >      > I didn’t quite understand this:
    >      >
    >      > “1/ Use SPARQL (interface RDFConnection) to connect to a remote triple
    >      >      store.  SPARQL tripe stores are very good at implementing the standards.”
    >      >
    >      > Does it mean that the graph DB I wanna use, should (out-of-the-box) support triples and SPARQL or this is the part that I should implement in order to use it with Jena?
    >      
    >      There are quiet a few SPARQL triple stores.  Choose and use.
    >      
    >      RDFConnection is part of the Jena codebase.
    >      
    >      >
    >      > Can you, please, point me, to examples how to:
    >      > 	
    >      > 1. Implement SQL adapter
    >      
    >      See the code for jena-sdb. This component is "maintenance only".
    >      
    >      > 2. Implement usage of alternative graph DB
    >      
    >      Choose your SPARQL triplestore, download and use!
    >      
    >      SPARQL and it's protocols are standards. The tripe store can be any one
    >      that implements the standards. In the SPARQL world, compliance levels
    >      are high.
    >      
    >      >
    >      > Happy holidays!
    >      > Stefan
    >      >
    >      >
    >      > On 12/21/17, 1:46 AM, "Andy Seaborne" <an...@apache.org> wrote:
    >      >
    >      >
    >      >
    >      >      On 21/12/17 04:41, Dimov, Stefan wrote:
    >      >      > Hi all,
    >      >      >
    >      >      > Where can I find more detailed info on how can use Jena with:
    >      >      >
    >      >      >
    >      >      >    1.  RDBMS
    >      >      >       *   Does it support just any RDBMS?
    >      >
    >      >      The supported databases are described in the documentation:
    >      >
    >      >      https://jena.apache.org/documentation/sdb/databases_supported.html
    >      >
    >      >      Note:
    >      >      [[
    >      >      Use of SDB for new applications is not recommended.
    >      >      This component is "maintenance only".
    >      >      TDB is faster, more scalable and better supported than SDB.
    >      >      ]]
    >      >
    >      >      >       *   If not, and I want to use it with different (from the supported) RDMS what should I do?
    >      >
    >      >      Do you need it to be an SQL database? (Someone was doing HAMA at one
    >      >      time but we didn't hear back from them).
    >      >
    >      >      You have to write the SQL adapter - SQL syntax, especially for DDL, is
    >      >      quite variable.  There are various examples to start with.
    >      >
    >      >      But SDB does not have the scale and speed of a native graph database.
    >      >
    >      >      >    1.  Alternative (not TDB) graph DB
    >      >      >       *   Is it possible
    >      >
    >      >      Yes.
    >      >
    >      >      1/ Use SPARQL (interface RDFConnection) to connect to a remote triple
    >      >      store.  SPARQL tripe stores are very good at implementing the standards.
    >      >
    >      >      2/ See if the store of your choice offers a Jena adapter.
    >      >
    >      >           Andy
    >      >
    >      >      >       *   If not, can it easily be done?
    >      >      >
    >      >      > Regards,
    >      >      > Stefan
    >      >      >
    >      >
    >      >
    >      
    > 
    


Re: Jena with RDBMS or alternative graph DB

Posted by Andy Seaborne <an...@apache.org>.
Big question. Details matter when considering the amount of work so I 
can only make general comments.

What's the interface to the graph ending part?  The public blogs (from 
2016/08) suggest its stored in a vertex table and an edge table held in 
the column store. The "graph algorthms" part is opaque.

Some snooping around says the current version has partial openCypher 
support. Mapping to that, and using the property graphs for easy mapping 
to/from SPARQL. Map the basic graph pattern to openCypther - or go to 
those tables, that's jena-sdb.

Oracle use Jena for their SPARQL - they plugin in at the basic graph 
pattern (or at least that was the state when I last heard).

Then the majority of SPARQL is Jena ARQ.

     Andy

On 03/01/18 23:02, Dimov, Stefan wrote:
> Thanks Andy,
> 
> I wanna clarify my questions.
> 
> In case we don’t use TDB, the alternative is already chosen (whether we like it or not). It’s a specific platform, that has both Graph and Relational DB that are very fast.
> 
> They both don’t have SPARQL adapters.
> 
> We want to avoid implementing SPARQL layers, so my question is:
> 
> In which case I would have less efforts (NOT implementing SPARQL layer), Relational DB adapter or Graph DB adapter, or in both cases I will need to implement and maintain the SPARQL layer?
> 
> Regards,
> Stefan
> 
> 
> 
> On 12/22/17, 4:41 PM, "Andy Seaborne" <an...@apache.org> wrote:
> 
>      
>      
>      On 23/12/17 00:15, Dimov, Stefan wrote:
>      > Thanks Andy,
>      >
>      > I didn’t quite understand this:
>      >
>      > “1/ Use SPARQL (interface RDFConnection) to connect to a remote triple
>      >      store.  SPARQL tripe stores are very good at implementing the standards.”
>      >
>      > Does it mean that the graph DB I wanna use, should (out-of-the-box) support triples and SPARQL or this is the part that I should implement in order to use it with Jena?
>      
>      There are quiet a few SPARQL triple stores.  Choose and use.
>      
>      RDFConnection is part of the Jena codebase.
>      
>      >
>      > Can you, please, point me, to examples how to:
>      > 	
>      > 1. Implement SQL adapter
>      
>      See the code for jena-sdb. This component is "maintenance only".
>      
>      > 2. Implement usage of alternative graph DB
>      
>      Choose your SPARQL triplestore, download and use!
>      
>      SPARQL and it's protocols are standards. The tripe store can be any one
>      that implements the standards. In the SPARQL world, compliance levels
>      are high.
>      
>      >
>      > Happy holidays!
>      > Stefan
>      >
>      >
>      > On 12/21/17, 1:46 AM, "Andy Seaborne" <an...@apache.org> wrote:
>      >
>      >
>      >
>      >      On 21/12/17 04:41, Dimov, Stefan wrote:
>      >      > Hi all,
>      >      >
>      >      > Where can I find more detailed info on how can use Jena with:
>      >      >
>      >      >
>      >      >    1.  RDBMS
>      >      >       *   Does it support just any RDBMS?
>      >
>      >      The supported databases are described in the documentation:
>      >
>      >      https://jena.apache.org/documentation/sdb/databases_supported.html
>      >
>      >      Note:
>      >      [[
>      >      Use of SDB for new applications is not recommended.
>      >      This component is "maintenance only".
>      >      TDB is faster, more scalable and better supported than SDB.
>      >      ]]
>      >
>      >      >       *   If not, and I want to use it with different (from the supported) RDMS what should I do?
>      >
>      >      Do you need it to be an SQL database? (Someone was doing HAMA at one
>      >      time but we didn't hear back from them).
>      >
>      >      You have to write the SQL adapter - SQL syntax, especially for DDL, is
>      >      quite variable.  There are various examples to start with.
>      >
>      >      But SDB does not have the scale and speed of a native graph database.
>      >
>      >      >    1.  Alternative (not TDB) graph DB
>      >      >       *   Is it possible
>      >
>      >      Yes.
>      >
>      >      1/ Use SPARQL (interface RDFConnection) to connect to a remote triple
>      >      store.  SPARQL tripe stores are very good at implementing the standards.
>      >
>      >      2/ See if the store of your choice offers a Jena adapter.
>      >
>      >           Andy
>      >
>      >      >       *   If not, can it easily be done?
>      >      >
>      >      > Regards,
>      >      > Stefan
>      >      >
>      >
>      >
>      
> 

Re: Jena with RDBMS or alternative graph DB

Posted by "Dimov, Stefan" <st...@sap.com>.
Does anybody has any personal experience in using D2RQ, ontop or any other  such SPARQL-over-RDBMS layer?

Please, share your experience, preference, comparison, obstacles, pros and cons …

S.

On 1/4/18, 10:07 PM, "Dimov, Stefan" <st...@sap.com> wrote:

    Thanks Marty, this might work …
    
    S.
    
    On 1/3/18, 3:55 PM, "Martynas Jusevičius" <ma...@atomgraph.com> wrote:
    
        Can't you use ontop or D2RQ to get RDF and SPARQL access?
        https://github.com/ontop/ontop
        
        On Thu, Jan 4, 2018 at 12:02 AM, Dimov, Stefan <st...@sap.com> wrote:
        
        > Thanks Andy,
        >
        > I wanna clarify my questions.
        >
        > In case we don’t use TDB, the alternative is already chosen (whether we
        > like it or not). It’s a specific platform, that has both Graph and
        > Relational DB that are very fast.
        >
        > They both don’t have SPARQL adapters.
        >
        > We want to avoid implementing SPARQL layers, so my question is:
        >
        > In which case I would have less efforts (NOT implementing SPARQL layer),
        > Relational DB adapter or Graph DB adapter, or in both cases I will need to
        > implement and maintain the SPARQL layer?
        >
        > Regards,
        > Stefan
        >
        >
        >
        > On 12/22/17, 4:41 PM, "Andy Seaborne" <an...@apache.org> wrote:
        >
        >
        >
        >     On 23/12/17 00:15, Dimov, Stefan wrote:
        >     > Thanks Andy,
        >     >
        >     > I didn’t quite understand this:
        >     >
        >     > “1/ Use SPARQL (interface RDFConnection) to connect to a remote
        > triple
        >     >      store.  SPARQL tripe stores are very good at implementing the
        > standards.”
        >     >
        >     > Does it mean that the graph DB I wanna use, should (out-of-the-box)
        > support triples and SPARQL or this is the part that I should implement in
        > order to use it with Jena?
        >
        >     There are quiet a few SPARQL triple stores.  Choose and use.
        >
        >     RDFConnection is part of the Jena codebase.
        >
        >     >
        >     > Can you, please, point me, to examples how to:
        >     >
        >     > 1. Implement SQL adapter
        >
        >     See the code for jena-sdb. This component is "maintenance only".
        >
        >     > 2. Implement usage of alternative graph DB
        >
        >     Choose your SPARQL triplestore, download and use!
        >
        >     SPARQL and it's protocols are standards. The tripe store can be any one
        >     that implements the standards. In the SPARQL world, compliance levels
        >     are high.
        >
        >     >
        >     > Happy holidays!
        >     > Stefan
        >     >
        >     >
        >     > On 12/21/17, 1:46 AM, "Andy Seaborne" <an...@apache.org> wrote:
        >     >
        >     >
        >     >
        >     >      On 21/12/17 04:41, Dimov, Stefan wrote:
        >     >      > Hi all,
        >     >      >
        >     >      > Where can I find more detailed info on how can use Jena with:
        >     >      >
        >     >      >
        >     >      >    1.  RDBMS
        >     >      >       *   Does it support just any RDBMS?
        >     >
        >     >      The supported databases are described in the documentation:
        >     >
        >     >      https://jena.apache.org/documentation/sdb/databases_
        > supported.html
        >     >
        >     >      Note:
        >     >      [[
        >     >      Use of SDB for new applications is not recommended.
        >     >      This component is "maintenance only".
        >     >      TDB is faster, more scalable and better supported than SDB.
        >     >      ]]
        >     >
        >     >      >       *   If not, and I want to use it with different (from
        > the supported) RDMS what should I do?
        >     >
        >     >      Do you need it to be an SQL database? (Someone was doing HAMA
        > at one
        >     >      time but we didn't hear back from them).
        >     >
        >     >      You have to write the SQL adapter - SQL syntax, especially for
        > DDL, is
        >     >      quite variable.  There are various examples to start with.
        >     >
        >     >      But SDB does not have the scale and speed of a native graph
        > database.
        >     >
        >     >      >    1.  Alternative (not TDB) graph DB
        >     >      >       *   Is it possible
        >     >
        >     >      Yes.
        >     >
        >     >      1/ Use SPARQL (interface RDFConnection) to connect to a remote
        > triple
        >     >      store.  SPARQL tripe stores are very good at implementing the
        > standards.
        >     >
        >     >      2/ See if the store of your choice offers a Jena adapter.
        >     >
        >     >           Andy
        >     >
        >     >      >       *   If not, can it easily be done?
        >     >      >
        >     >      > Regards,
        >     >      > Stefan
        >     >      >
        >     >
        >     >
        >
        >
        >
        
    
    


Re: Jena with RDBMS or alternative graph DB

Posted by "Dimov, Stefan" <st...@sap.com>.
Thanks Marty, this might work …

S.

On 1/3/18, 3:55 PM, "Martynas Jusevičius" <ma...@atomgraph.com> wrote:

    Can't you use ontop or D2RQ to get RDF and SPARQL access?
    https://github.com/ontop/ontop
    
    On Thu, Jan 4, 2018 at 12:02 AM, Dimov, Stefan <st...@sap.com> wrote:
    
    > Thanks Andy,
    >
    > I wanna clarify my questions.
    >
    > In case we don’t use TDB, the alternative is already chosen (whether we
    > like it or not). It’s a specific platform, that has both Graph and
    > Relational DB that are very fast.
    >
    > They both don’t have SPARQL adapters.
    >
    > We want to avoid implementing SPARQL layers, so my question is:
    >
    > In which case I would have less efforts (NOT implementing SPARQL layer),
    > Relational DB adapter or Graph DB adapter, or in both cases I will need to
    > implement and maintain the SPARQL layer?
    >
    > Regards,
    > Stefan
    >
    >
    >
    > On 12/22/17, 4:41 PM, "Andy Seaborne" <an...@apache.org> wrote:
    >
    >
    >
    >     On 23/12/17 00:15, Dimov, Stefan wrote:
    >     > Thanks Andy,
    >     >
    >     > I didn’t quite understand this:
    >     >
    >     > “1/ Use SPARQL (interface RDFConnection) to connect to a remote
    > triple
    >     >      store.  SPARQL tripe stores are very good at implementing the
    > standards.”
    >     >
    >     > Does it mean that the graph DB I wanna use, should (out-of-the-box)
    > support triples and SPARQL or this is the part that I should implement in
    > order to use it with Jena?
    >
    >     There are quiet a few SPARQL triple stores.  Choose and use.
    >
    >     RDFConnection is part of the Jena codebase.
    >
    >     >
    >     > Can you, please, point me, to examples how to:
    >     >
    >     > 1. Implement SQL adapter
    >
    >     See the code for jena-sdb. This component is "maintenance only".
    >
    >     > 2. Implement usage of alternative graph DB
    >
    >     Choose your SPARQL triplestore, download and use!
    >
    >     SPARQL and it's protocols are standards. The tripe store can be any one
    >     that implements the standards. In the SPARQL world, compliance levels
    >     are high.
    >
    >     >
    >     > Happy holidays!
    >     > Stefan
    >     >
    >     >
    >     > On 12/21/17, 1:46 AM, "Andy Seaborne" <an...@apache.org> wrote:
    >     >
    >     >
    >     >
    >     >      On 21/12/17 04:41, Dimov, Stefan wrote:
    >     >      > Hi all,
    >     >      >
    >     >      > Where can I find more detailed info on how can use Jena with:
    >     >      >
    >     >      >
    >     >      >    1.  RDBMS
    >     >      >       *   Does it support just any RDBMS?
    >     >
    >     >      The supported databases are described in the documentation:
    >     >
    >     >      https://jena.apache.org/documentation/sdb/databases_
    > supported.html
    >     >
    >     >      Note:
    >     >      [[
    >     >      Use of SDB for new applications is not recommended.
    >     >      This component is "maintenance only".
    >     >      TDB is faster, more scalable and better supported than SDB.
    >     >      ]]
    >     >
    >     >      >       *   If not, and I want to use it with different (from
    > the supported) RDMS what should I do?
    >     >
    >     >      Do you need it to be an SQL database? (Someone was doing HAMA
    > at one
    >     >      time but we didn't hear back from them).
    >     >
    >     >      You have to write the SQL adapter - SQL syntax, especially for
    > DDL, is
    >     >      quite variable.  There are various examples to start with.
    >     >
    >     >      But SDB does not have the scale and speed of a native graph
    > database.
    >     >
    >     >      >    1.  Alternative (not TDB) graph DB
    >     >      >       *   Is it possible
    >     >
    >     >      Yes.
    >     >
    >     >      1/ Use SPARQL (interface RDFConnection) to connect to a remote
    > triple
    >     >      store.  SPARQL tripe stores are very good at implementing the
    > standards.
    >     >
    >     >      2/ See if the store of your choice offers a Jena adapter.
    >     >
    >     >           Andy
    >     >
    >     >      >       *   If not, can it easily be done?
    >     >      >
    >     >      > Regards,
    >     >      > Stefan
    >     >      >
    >     >
    >     >
    >
    >
    >
    


Re: Jena with RDBMS or alternative graph DB

Posted by Martynas Jusevičius <ma...@atomgraph.com>.
Can't you use ontop or D2RQ to get RDF and SPARQL access?
https://github.com/ontop/ontop

On Thu, Jan 4, 2018 at 12:02 AM, Dimov, Stefan <st...@sap.com> wrote:

> Thanks Andy,
>
> I wanna clarify my questions.
>
> In case we don’t use TDB, the alternative is already chosen (whether we
> like it or not). It’s a specific platform, that has both Graph and
> Relational DB that are very fast.
>
> They both don’t have SPARQL adapters.
>
> We want to avoid implementing SPARQL layers, so my question is:
>
> In which case I would have less efforts (NOT implementing SPARQL layer),
> Relational DB adapter or Graph DB adapter, or in both cases I will need to
> implement and maintain the SPARQL layer?
>
> Regards,
> Stefan
>
>
>
> On 12/22/17, 4:41 PM, "Andy Seaborne" <an...@apache.org> wrote:
>
>
>
>     On 23/12/17 00:15, Dimov, Stefan wrote:
>     > Thanks Andy,
>     >
>     > I didn’t quite understand this:
>     >
>     > “1/ Use SPARQL (interface RDFConnection) to connect to a remote
> triple
>     >      store.  SPARQL tripe stores are very good at implementing the
> standards.”
>     >
>     > Does it mean that the graph DB I wanna use, should (out-of-the-box)
> support triples and SPARQL or this is the part that I should implement in
> order to use it with Jena?
>
>     There are quiet a few SPARQL triple stores.  Choose and use.
>
>     RDFConnection is part of the Jena codebase.
>
>     >
>     > Can you, please, point me, to examples how to:
>     >
>     > 1. Implement SQL adapter
>
>     See the code for jena-sdb. This component is "maintenance only".
>
>     > 2. Implement usage of alternative graph DB
>
>     Choose your SPARQL triplestore, download and use!
>
>     SPARQL and it's protocols are standards. The tripe store can be any one
>     that implements the standards. In the SPARQL world, compliance levels
>     are high.
>
>     >
>     > Happy holidays!
>     > Stefan
>     >
>     >
>     > On 12/21/17, 1:46 AM, "Andy Seaborne" <an...@apache.org> wrote:
>     >
>     >
>     >
>     >      On 21/12/17 04:41, Dimov, Stefan wrote:
>     >      > Hi all,
>     >      >
>     >      > Where can I find more detailed info on how can use Jena with:
>     >      >
>     >      >
>     >      >    1.  RDBMS
>     >      >       *   Does it support just any RDBMS?
>     >
>     >      The supported databases are described in the documentation:
>     >
>     >      https://jena.apache.org/documentation/sdb/databases_
> supported.html
>     >
>     >      Note:
>     >      [[
>     >      Use of SDB for new applications is not recommended.
>     >      This component is "maintenance only".
>     >      TDB is faster, more scalable and better supported than SDB.
>     >      ]]
>     >
>     >      >       *   If not, and I want to use it with different (from
> the supported) RDMS what should I do?
>     >
>     >      Do you need it to be an SQL database? (Someone was doing HAMA
> at one
>     >      time but we didn't hear back from them).
>     >
>     >      You have to write the SQL adapter - SQL syntax, especially for
> DDL, is
>     >      quite variable.  There are various examples to start with.
>     >
>     >      But SDB does not have the scale and speed of a native graph
> database.
>     >
>     >      >    1.  Alternative (not TDB) graph DB
>     >      >       *   Is it possible
>     >
>     >      Yes.
>     >
>     >      1/ Use SPARQL (interface RDFConnection) to connect to a remote
> triple
>     >      store.  SPARQL tripe stores are very good at implementing the
> standards.
>     >
>     >      2/ See if the store of your choice offers a Jena adapter.
>     >
>     >           Andy
>     >
>     >      >       *   If not, can it easily be done?
>     >      >
>     >      > Regards,
>     >      > Stefan
>     >      >
>     >
>     >
>
>
>