Skip to Content

SAP HANA Dynamic Tiering on Disk or In-Memory

Hi Experts,


I am trying to understand when dynamic tiering generate Pview (Union of Hot-To-Cold), So when I do Select * From Pview where the query will run will it be on Disk or In-Memory?

Add comment
10|10000 characters needed characters exceeded

  • Follow
  • Get RSS Feed

1 Answer

  • Sep 21, 2016 at 06:29 AM

    Hi Santhosh,

    In Dynamic Tiering, HOT data is stored in In-memory and will be processed in In-memory itself.

    [In-memory Tables - algorithms used to access the data are optimized for in-memory data].

    In Dynamic Tiering, Cold data is stored in Extended storage [SAP IQ DB] and will be processed in disk. [Extended Tables - algorithms used to access the data are optimized for disk-based data].


    So for your scenario, while retrieving the data from PView,

    Dynamic Tiering HOT data will be processed in HANA In-memory and

    Dynamic Tiering COLD data will be processed in SAP IQ DB disk.


    Regards,

    Muthuram



    Add comment
    10|10000 characters needed characters exceeded

    • Hi Santhosh,

      I understand the Issue faced.

      Can you please check the following things and let me know the results.

      1. Create Columnar Table (T_Inmemory) with 2 Columns - ID & Name and

      Make it Column - ID as Primary Key.

      2. Insert Data to the Table ranging 1 to 10.

      3. Create Extended Storage Table (T_Extended) with same structure

      4. Move all the records from In-Memory Table to Extended Table.

      5. Now Insert record (1, Mr.A) Columnar Table (T_Inmemory).


      If this record is Inserted, We will have two record for Employee ID - 1.

      In this case, Please raise Message and contact SAP support for help.

      We can do this as a workaround solution.

      Deleting the record (Employee ID - 1) from Extended Storage.


      Regards,

      Muthuram