Re: Index Calculation Question

The Row entry header is 2 bytes.

Also, since the rowid is appended to the data columns when you have a non-unique index, the cost of the rowid is 7 bytes for a non-unique rather than 6 bytes for a unique index.

alter session set event 'immediate trace name blockdump level {block no}';

if you want to check it in detail.

However, since any calculation of the branch block usage is so rough, I don't think you don't really need to worry too much about high precision arithmetic.

-- 
Jonathan Lewis