Joined: 06 Dec 2004 Posts: 211 Location: Keane Inc., Minneapolis USA.
1.A synonym is used to reference a table or view by another name. The other name can then be written in the application code pointing to test tables in the development stage and to production entities when the code is migrated.The synonym is linked to the AUTHID that created it.
CREATE [PUBLIC] SYNONYM tabspaces FOR sys.dba_tablespaces
2. Views are virtual tables ? that is, they are collections of columns from related tables that are defined in a way such that they make it easier for a user to access needed information from a database.
For example, a salesperson may be accustomed to viewing sales orders according to the traditional sales order form that the firm uses. In most firms, the sales order requires data from the CUSTOMERS, ORDERS, ORDERLINE, and PRODUCTS tables.
3. An alias is an alternative to a synonym, designed for a distributed environment to avoid having to use the location qualifier of a table or view. The alias is not dropped when the table is dropped.