DBMS/SQL Quiz 1

In generalization we combine lower level entities to form a higher level entity. Thus it's clear that it follows a bottom up approach.

SQL, mySQL,noSQL,Oracle,IBM DB2, PostgreSQL, MongoDB are examples of DBMS.

rownum is a clause in SQLwhich is used to specify the number of tuples present in a database table.

All large dynamic web applications present over the internet or examples of this 3 tier architecture.

Operational is not a DBMS Models.
DBMS models are : Flat File, Network, Relational, Object-Relational, Hierarchical.

Network model uses many to many relationships where the child only is allowed to have more than one parent node as a result a large number of relationships can be applied with different data tables and data access becomes easier and faster .

Horizontal Dashed Oval is used to represent the Derived Attributes in ER Diagrams.

Composite attributes are the attribute that can be divided further into more than one attribute i.e an attribute can have further sub-attributes.

Many students can study in a single college but the student cannot study in more than one college at the same time.

Relationship between two entities of the same type is called recursive relationship. A Recursive relationship is nothing but, simply an entity is having a relationship with self.