identity columns ?

Hello,

Two questions -

1. M$ SQL Server has an identity column which generates a sequential number
for you, we use this often for unique primary keys. Does postgres support
anything like  this ?


2. We're using pg-admin to work with postgres. It doesn't seem possible to
modify tables in pg-admin once you've created them, you have to delete and
add. Is there another pg client that supports modifying tables ?

Tia,
Chris