Subject Re: [firebird-support] Space consuming test
Author Ivan Prenosil
> The point of this test : lets say we have big table TB_ORDERS > 30mil
> records. And we need to add new row ADDITIONAL_COMMENTS (varchar 1600) ,
> which by normalization theory should go into that table. BUT this row
> will be used only for 0.1%.So, this means 99.9% of that coll will be
> used as waste (28bytes * 29700000 ~ 831 MB ). (Of course other solution
> one - to - one ref link)

Looking at your new field's name, and considering 0.1% usage,
I would use BLOB. (null blob will consume 2 bytes, or even less
if physically grouped with other zero data on the row)