> This is the most obvious effect - if you’re returning 800 columns instead of 8 columns from every row, you could end up sending 100x more bytes over the netwo

> This is the most obvious effect - if you’re returning 800 columns instead of 8 columns from every row, you could end up sending 100x more bytes over the network for every query execution. In theory, this makes sense, but 800 column is already another problem for your application/system. What if you need to select 196 of those columns, what are you going to do? What kind of SQL or Java/Python/NAME_HERE_OTHER_LANG code are you going to write to select those fields?