Well.. this is a very old thread but still 2 cents from me for those who will still visit here. This link has the best answer for the above query.
An excerpt from the same:
SQL Server ships with ten pre-defined schemas that have the same ...
From my point of view some confusion regarding the terms "database", "schema" and "user" also comes from the differences between Microsoft SQL Server and Oracle.
"Inside" Oracle the difference between schema and user/login is not to be understood without further explanation. "User" is an account to log in to the database (usually without own objects like ...
The db_datareader, db_datawriter, and db_ddladmin permissions will not give the necessary privilege for this action.
db_datareader: Members of the db_datareader fixed database role can read all data from all user tables.
db_datawriter: Members of the db_datawriter fixed database role can add, delete, or change data in all user tables.
Indexes use space, and a 16 byte key is nothing to worry about.
So you should define the primary key on user_relations on (relating_user_id, related_user_id). If you need to search by relation_type, it won't help to put the column into the INCLUDE list, since such columns cannot be used as filter for an index scan.
I see two options:
In addition to the ...