Relation between Statistics and Indexes on a table - forum topic by mayya@teradataforum

Hi,
I have created a table "product" with defination as below,
CREATE SET TABLE product ,NO FALLBACK ,
     NO BEFORE JOURNAL,
     NO AFTER JOURNAL,
     CHECKSUM = DEFAULT
     (
      product_id INTEGER,
      product_name VARCHAR(20) CHARACTER SET LATIN NOT CASESPECIFIC,
      sale_date DATE FORMAT 'dd-mm-yyyy',
      daily_sales DECIMAL(18,6))
PRIMARY INDEX ( product_id );
presently there are 10 rows in it.
Now i collected stats on column (product_name,  sale_date) as below,
---  collect statistics  product  column (product_name,sale_date) ;

then i try to drop column sale_date from "product" table as below,
alter table product
drop  sale_date    ;
But it gaves me an error "3557 : column sale_date is an Index column and cannot be dropped".
I think statistics which i collected got inserted into DBC.Indexes because of which it is telling me this error (even though there are no index defined on sale_date column).
But please put some light on this issue as I am still not pretty sure about it.