In the table that defines the categories and sub-categories for a navigation bar some links have subcategories (like accessories; narrow down the search by manufacturer, product model, etc) and some have none (like products; if you click latest products it shows the latest products, no subcategories).
Another example is I intend to include accessories and products in the same table. An accessory only requires a couple of images at most. A product will feature at least 4 images. There will be a field for image names… for accessories some cells will be blank. Furthermore, I might have 3 fields for product content (text) whereas with accessories it requires less text to explain what it can do (probably use 1 of the 3 content fields).
I am most interested in understanding the problems with leaving blank cells so I can consider whether I should bother to avoid it!?
Blank cells vs no column? No column is slightly quicker IF you arnt joining the table.
Blank cells vs filled cells? Filled cell will take longer to transmit unless it’s a null string. (And… even then i think it might be longer because the server sends the \0)
Blank cells vs seperate table that’s being JOIN’d? Rudy might correct me here, but i believe seperate-and-joined tables would be slower (since the server has to go through the compilation process)
That said, unless you’re pulling massive tables or handling a huge userload, the difference in timing will be measured in microseconds at best, and generally does not bare thinking about…
I know that. Just funny to call them that if unless you are thinking about a database like a spreadsheet. If you are doing that then you are doomed to fail anyhow.
As for the problem at hand, I really don’t think it would matter enough to be measurable unless the underlying storage is horribly designed and needs to do funny things to deal with blank columns in a row.