3 Replies Latest reply on Jun 13, 2014 6:22 AM by Dave Ballantyne

    Some newbie questions

    Dave Ballantyne Newbie

      Hi there,

       

      I have a few simple questions about teiid and perhaps even data virtualization in general.

       

      We have two SQL source systems , which for the sake of argument are tables which with exactly the same schema and we need an effective UNION ALL.

      These are over unreliable and high latency lines, so what is the impact of the virtualized layer if one or other of those sources is unavailable ? . 

      My google-fu maybe failing but i cant find a simple answer to this, what i would imagine be a fundamental question.


      Also,  If both tables are "customers" both with ids starting at 1,  how would we go about creating new surrogate keys or would the simplest thing be to create a composite key of <Server>,<CustomerId> ?


      Thanks


      Dave

       

        • 1. Re: Some newbie questions
          Steven Hawkins Master

          > These are over unreliable and high latency lines, so what is the impact of the virtualized layer if one or other of those sources is unavailable ?


          One of several things.  You can let the query error out.  You can set what's called partial results mode and we'll make a best effort.  Or you can use delegating translator or other mechanism to insert customized error handling.


          > Also,  If both tables are "customers" both with ids starting at 1,  how would we go about creating new surrogate keys or would the simplest thing be to create a composite key of <Server>,<CustomerId> ?

           

          If each source represents different entities, then yes a composite key that includes the source/server would work well.


          1 of 1 people found this helpful
          • 2. Re: Some newbie questions
            Van Halbert Master

            If the schemas are the same, you could use the multi-source models option.  Which, by default, will perform a union across the multiple sources, and will bypass a source if its off-line.    And using the composite key would work.

            1 of 1 people found this helpful
            • 3. Re: Some newbie questions
              Dave Ballantyne Newbie

              Thanks for the Info