Skip to Content

NBIT compression scheme was introduced as new feature in SAP IQ 16. It uses n bits to index the dictionary where the data is stored. Attached document provides some details on the index, its usage and behaviour.


NBIT Dictionary Compression (NBIT Index) – SAP IQ – SCN Wiki

To report this post you need to login first.

4 Comments

You must be Logged on to comment or reply to a post.

  1. Volker Stöffler

    Hi Harpreet,

    I thought it might be useful for unique or primary key columns (where s ingle column is unique) to declare them as IQ UNIQUE (0). Thus they would be forced to a Flat FP index from the beginning since there is no benefit from dictionary compression due to a lack of repeating values. Do you agree to this consideration?

    Thanks & regards

    Volker

    (0) 
      1. Rey Wang

        I have the SP08 PL30, and the table has varchar(300) column with lots of data in it.

        But somehow sp_iqindexrebuildwidedata return BLANK back.

        Can you create a table with wide column table and load some data; run describe and verify this system proc still works as expected.

        Thanks

        (0) 
        1. Harpreet Chaudhary Post author

          Hi Rey,

          Yes works fine. Here is my test :

          1. create table t_wide (a int, b varchar(300))

          2. Insert some rows of data

          select count(*) from t_wide

          4

          3. sp_iqindexrebuildwidedata(‘t_wide’)

          Owner,Table,Column,Domain,Width,IndexType,sp_iqrebuild

          ‘DBA’,’t_wide’,’b’,’varchar’,300,’2 Bit FP’,’sp_iqrebuildindex ””DBA.t_wide”” , ”column “b” 0” ;’

          If you ran the stored proc on demo database, you should see output for Products table that contains a wide column as well.

          Regards

          Harpreet

          (0) 

Leave a Reply