3 Replies Latest reply on Aug 26, 2009 4:11 PM by Ramesh Reddy

    multiple vdblessdef

    Moti Ram Newbie

      Hi all,

      I would like to deply multiple vdblessdef files to the engine.

      the questions are :
      1. can It be done?
      2. how i deply it to the JBossAS (Do I need a data source for each vdblessdef?)?

      any thoughts and suggestions will be helpfull.


        • 1. Re: multiple vdblessdef
          Ramesh Reddy Master


          1) Yes, you can deploy multiple VDBs (does not matter if they are actual VDB created using the Designer or simple XML DEF file) in a given Teiid runtime.

          However, you have to make different JDBC connections for each VDB separately from your client application to access Teiid.

          2) Copy your "vdblessdef" file(s) into the deploy directory. Please note that in this XML file you will be providing connection properties for all the sources you are trying to integrate. There is an example in the Teiid download. Yes, you would then create a data source for each VDB in the JBoss AS. For deploying into JBoss follow instructions at

          the instructions say they for embedded, but they should hold same for server mode too. We will be updating these very soon.

          Thank you for considering Teiid for your data integration needs.


          • 2. Re: multiple vdblessdef
            Moti Ram Newbie

            Thanks for the info rareddy.

            I would like to ask two more questions.

            1. how do I handle the situation where the same column name exist in two data sources?
            2. Does any one know when the virtual layer will be available in the vdblessdef?


            • 3. Re: multiple vdblessdef
              Ramesh Reddy Master


              1) If there are conflicting named Tables in two different sources, they can be qualified with the Model name they are defined under. See the xml format at


              look at the element. For example if you have

              "ModelA" has connector "Connect1" with Table "Foo"
              "ModelB" has connector "Connect2" with Table "Foo"

              you can write queries like

              select * from ModelA.Foo
              select * from ModelB.Foo
              select a.*, b.* from ModelA.Foo as a, ModelB.Foo as B where a....

              2) VDB Less feature will not provide the Virtual Layer (defining the abstractions on top of source layers). This is designed to quickly integrate data between multiple source layers. If you require the virtual layers, then you can take the full modelling approach to design a VDB using the Teiid Designer. Those features are will be always available in Teiid.

              What Teiid is trying achieve is cater to needs of the user, who may need quick integration without abstraction, for them vdbless (we need a better name for this) is better solution, otherwise take the VDB approach.

              In 6.3 ~ 7.0 time frame we are planning to define and provide metadata in terms of DDL. With this you would be able to use DDL along with some language extensions to define a virtual layer of your choosing, thus building a virtual schema that can be deployed in a Teiid runtime. Currently you can only use Designer to build the VDB. This proposal is currently being discussed in Teiid dev channels, we would appreciate any input in driving this feature.

              I think I gave the old link before for the JBossAS deployment, here is the revised document written for 6.2 release