Question

I create a column as primary key , does this create indexes automatically ? or do i need to create indexes explicitly. i was under assumption that primary key also maintains indexes

Answer 1

In SQL Server creating a Primary key will create a Unique Clustered Index on that Column.
or more specifically from here

Note PRIMARY KEY constraints create
clustered indexes automatically if no
clustered index already exists on the
table and a nonclustered index is not
specified when you create the PRIMARY
KEY constraint.