>>You don't have to create a trigger for each column. One trigger per table can handle all columns in it.
>>
>
>I didn't know that. Thank you.
>
>But still, I have about 90 tables in the database. Not all of them will need a trigger but say, maybe half of them. Is this reasonable?

It doesn't sound right to me but you have to provide more details on why you need them to draw proper conclusions