2 Replies Latest reply: Jun 27, 2012 9:42 AM by 933318 RSS

    Move Partition from HP Disks to HC Disks

    Saurabh Gupta-OC
      Dear All,

      We have Exadata -V2 quarter rack with High Performance Disks. We applied EHCC's various compression methods on some of the table's partitions.

      Now we are setting up Exadata Expansion Rack - High Capacity Disks.

      Post implementation, we would be moving older partitions to new Expansion Rack wherein compressed partitions are also included.

      In this case, would there be any impact on the compression ratio as the expansion rack is having high capacity disks.

      And, moving partition method would be same as it is for non-exadata database i.e. "alter table <table_name> move partition <partition_name> tablespace <tablespace_name>"

      Please suggest.

      Regards,
      Saurabh
        • 1. Re: Move Partition from HP Disks to HC Disks
          Andy Klock
          877938 wrote:
          In this case, would there be any impact on the compression ratio as the expansion rack is having high capacity disks.
          The compression ratio will be unaffected since it is determined by the data itself and not where it is stored. Where you may feel the affects is with the slower IOPS of your new high capacity disks.
          And, moving partition method would be same as it is for non-exadata database i.e. "alter table <table_name> move partition <partition_name> tablespace <tablespace_name>"
          Correct, unless it is possible for you to use transportable tablespaces. That would most likely be preferred. If that won't work for your environment, a couple of things to keep in mind, was the compression configured at the tablespace, table, or partition level? You want to make sure your compression intentions are persisted as you move to the new tablespaces.

          And don't forget your indexes :)
          • 2. Re: Move Partition from HP Disks to HC Disks
            933318
            Compression ratio will not be affected because of the high capacity disks(The indvidual disks are 2tb*12 running at a much lower RPM 7.2k)