Instead of using a single string or integer value, does anyone uses arrays in database fields?

For example, instead of storing a single email address for a record, I could use an array to
store up to 5 email addresses for a person.

Does using arrays in fields degrade database performance in any way?

You cannot store an array. The best you could do is store 5 strings with a suitable separator, but really that's bad design. Its more efficient to use a separate table to store the multiple email addresses along with the necessary primary key to relate the email records back to the other table which contains each person's record.

Thanks for the info. I'm looking at everything from a programmatically point of view.
I was wondering how a SQL query command could even process an array and search for the right
string. Guess it isn't possible.