Do I need a “random salt” once per password or only once per database?

Question

Further to my previous question about salted passwords in PHP/MySQL, I have another question regarding salts.

When someone says \"use a random salt\" to pre/append t

Answer 1

The second alternative is the correct one.

Traditionally, the salt is stored alongside with the hashed password, but non encrypted (typically preappended, for example in unix passwords)

Update: the method used in most newer Unix system is this one.