Subject Re: [firebird-support] Database design. Simple question!
Author Aldo Caruso

My advice is to create that field in the invoices table.

You will always have this field at hand without resorting to an outer join with another table that only has two fields ( the invoice ID and this field ) each time you need to inspect it.


El 25/07/16 a las 18:51, shg_sistemas@... [firebird-support] escribió:

Hello! I  have a FB 2.5 database with a tabla "invoices". I need to add a field in that table which will be null most of the times. Lefts say, that 90% of the records will have this new field in null. 

What is your advice? To create a new table with a FK to "invoices" and save the needed field in a separate table (only when the value is not null of course) of just create the new field in the main "invoices" table?

I think I read somewhere that null fields use very little space in the database. Is that true?

Thanks for any input!!!