SAP IQ 16 nBit Indexes some details
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
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
I agree, thank you. I will edit the doc and add your comment.
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.
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
'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.