Say I have a database with 1 million rows, each row has a BLOB column so can vary in size from about 30bytes to 1MB, but averaging around 1K/row

There are two indexes - one for the primary key and a secondary index for one integer column.

If I didn't account for overhead, I'd say that this would take up around 1million x 1000 bytes or 1GB + 1 million x 8bytes or 8MB for the secondary index.

But that's assuming a "perfect" layout for the database.  I am wondering, how much overhead should I account for?  



David W. Van Couvering