Should all database tables have a primary key?

Question

Is it good practice to give every database table a primary key? It seems to me that if the primary key is not explicitly needed, then it would just be extra clutter in my d

Answer 1

I have a table that is partitioned by CreateDate which is not unique. In my case I have decided to remove the primary key from this table because the fact that a primary key index must be unique meant that I couldn't make this index a LOCAL index, instead it has to be GLOBAL. This would have meant that any deletion from that table (amongst other actions) would have made this primary key index unusable, rendering it useless.