1 2 Previous Next 20 Replies Latest reply: Jan 9, 2012 1:42 PM by Charles Lamb Go to original post RSS
      • 15. Re: Adding more nodes later
        906230
        Hi Charles,

        When a record is stored on a node, is the partition also stored along with the record?

        Thanks
        • 16. Re: Adding more nodes later
          Charles Lamb
          user962305 wrote:
          Hi Charles,

          When a record is stored on a node, is the partition also stored along with the record?
          No. The record is stored in a partition. A partition is a JE Database in a JE Environment. A Rep Group is a JE Replicated Environment. A Rep Group contains many partitions (JE Databases). A partition contains one or more key/value pairs.

          Charles
          • 17. Re: Adding more nodes later
            896774
            Charles,

            What I was trying to understand is how can data be redistributed if there is not link between record and partition stored some where?
            Since the granularity for redistribution is partition, I agree we can identify the replication group (and therefore nodes in the replication group). But will we identify the data to redistribute?
            Thanks
            • 18. Re: Adding more nodes later
              Charles Lamb
              We hash the key to get to a partition id. We then look up the partition id in a mapping table. If we migrate a partition, we change the mapping table. A key always maps to the same partition, no matter where it lives. The mapping table is persistent in the topology.

              Charles Lamb

              Edited by: Charles Lamb on Jan 7, 2012 10:00 AM
              • 19. Re: Adding more nodes later
                896774
                Hi Charles,

                Let's say, we have partition 1, partition 3 and partition 7 on Server Node 1.
                If we want to migrate partition 1, how will we know records that are in partition 1?
                We know that those records are on Server Node 1 but how does Oracle NoSQL identify records related to a partition?
                Thanks.
                • 20. Re: Adding more nodes later
                  Charles Lamb
                  893771 wrote:
                  Hi Charles,

                  Let's say, we have partition 1, partition 3 and partition 7 on Server Node 1.
                  If we want to migrate partition 1, how will we know records that are in partition 1?
                  We know that those records are on Server Node 1 but how does Oracle NoSQL identify records related to a partition?
                  A partition is a JE Database. We just look in the database to find all the records for that partition/database. Retrieving all records in a database is a simple matter using the JE API.

                  Charles Lamb
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