Explore topic-wise MCQs in Engineering.

A supertype can only have only one subtype.

Symmetric multiprocessing (SMP) architectures are useful for situations where data must remain in memory during processing to achieve the desired performance level.

There is cardinality on an EER between the supertype and subtype.

A subtype discriminator of the supertype is an attribute whose values determine the target subtype(s).

The Windows operating system and Windows applications are event driven.

The SQL MAKE TABLE command is used to construct tables, define columns, define column constraints and create relationships.

SQL has a JOIN ON syntax that can be used to create inner joins and outer joins.

Standard SQL-92 views are constructed from SQL SELECT statements that do not contain the GROUP BY clause.

The SQL CHECK constraint is fully defined by the SQL-92 standard, and is consistently implemented by all DBMS vendors.

A regular subquery is processed from the bottom up.

Correlated subqueries are similar to a regular subquery.

Database redesign is especially difficult if the database has no data.

A correlated subquery is processed as a nested subquery.

Some organizations take the stand that no application should ever employ the true name of a table.

A method defines the form or protocol of the operation, but not its implementation.

A class is a concept, abstraction, or thing that makes sense in an application context.

ODL supports the abstract keyword for classes and operations.

The ODMG Object Model requires that a relationship be specified in both directions.

Before specifying a key for a class, you must specify its extent.

The Object Model supports different literal types, but does not support atomic literals, collection literals, and structured literals.

An ID-dependent entity is an entity whose identifier is a composite identifier where no portion of the composite identifier is an identifier of another entity.

All instances of an entity class have the same attributes.

A ternary relationship is so called because in contains two entities and one association between them.

A minimum cardinality is the minimum number of entity instances that may participate in a relationship instance.

An attribute describes the entity's characteristics.

Indexes are created to enforce uniqueness on columns and to enable fast retrieval by column values.

An entity is something that can be identified in the user's work environment; something that the users want to track.

Entity instances are associated by relationship classes.

1:1, 1:N and N:M relationships are also known as HAS-A relationships.

In a 1:N relationship, the parent is the entity on the one side of the relationship and the child is the entity on the N side of the relationship.

A maximum cardinality is the maximum number of entity instances that can participate in a relationship instance.

Composite identifiers consist of two or more attributes.

When designing a database, first identify the entities, then determine the attributes, and finally establish the relationships.

A subtype entity is a special case of another entity called a supertype entity.

The reasons for overriding include extension, restriction, and optimization.

An object's state is determined by its attribute values and links to other objects.

Composition does not allow an object to be part of more than one aggregate object.

In an object diagram, an object is represented as a rectangle with two compartments.

An operation that alters the state of an object is known as a constructor operation.

Each association has two or more roles.

The data model produced from the reverse engineering process is a true logical model.

Reverse engineering is the process of reading a database schema and producing a data model from that schema.

It is not easy to build a database correctly the first time.

Typically, there should be at least two different copies of the database schema used in the redesign process.

Dependency graphs are diagrams that consist of nodes and arcs that show the dependencies of a database.

The EXISTS keyword will be true if any row in the subquery meets the condition.

Although creating test databases is a critical and necessary job, there are few career opportunities in this area.

Because of the need for extensive knowledge of SQL, many database developers choose to automate the redesign process.

You can use the DROP statement to remove structures from the database.

Oracle commands, column names, table names, view names and all other database elements are case sensitive.