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1 2 Previous Next 20 Replies Latest reply: Jan 9, 2012 11:42 AM by Charles Lamb Go to original post RSS
  • 15. Re: Adding more nodes later
    906230 Newbie
    Currently Being Moderated
    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 Pro
    Currently Being Moderated
    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 Newbie
    Currently Being Moderated
    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 Pro
    Currently Being Moderated
    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 Newbie
    Currently Being Moderated
    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 Pro
    Currently Being Moderated
    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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