Computer & IT

note!Answer: C) Procedural query Language
Relational algebra is a procedural query language because it specifies the operations and their order to obtain results.

note!Answer: C) Foreign Key
A foreign key is an attribute in one table that references the primary key of another table, linking them.

note!Answer: D) both (A) and (B)
A DBMS provides data independence and centralized control of data, which are key advantages of database systems.

note!Answer: C) (A) and (B) both are true
In a relational model, rows have no inherent order and every row must be distinct, so both statements are true.

note!Answer: D) independent of both hardware and software.
The conceptual model describes data and relationships at a logical level, independent of any hardware or software.

note!Answer: B) Binary
A relationship between two entities is called a binary relationship. Unary involves one entity, and ternary involves three.

note!Answer: A) PROJECTION
The projection operation selects specific columns from a table. Selection picks rows instead.

note!Answer: D) All of the above
CHARACTER, NUMERIC and FLOAT are all standard SQL data types.

note!Answer: A) tuple.
In relational database terminology, a row is called a tuple, a column is an attribute, and a table is a relation.

note!Answer: D) All of the above
Union, intersection and difference all require the operand relations to have the same number of attributes with compatible domains.

note!Answer: C) Data Definition Language
DDL stands for Data Definition Language, used to create and modify database structures.

note!Answer: B) Naïve users.
Naive users interact with the database through easy-to-use menus or forms without programming knowledge.

note!Answer: A) External
The external level (view level) is closest to users and shows only the part of the database they need.

note!Answer: B) Total and partial
Entity participation in a relationship is either total (mandatory) or partial (optional).

note!Answer: C) all the tuples of R1 and R2
UNION combines all tuples from both relations, with duplicates removed.

note!Answer: D) domain.
A domain is the set of all possible atomic values that an attribute can take.

note!Answer: C) Relational algebra
Relational algebra provides the basic procedural operations (select, project, union, etc.) for manipulating relational data.

note!Answer: C) view
A view is a virtual table defined by a query and does not store data physically.

note!Answer: A) Network Model
The network, relational, and hierarchical models are record-based logical models. The E-R model is a conceptual model, and the object-oriented model is not record-based.

note!Answer: A) SELECT
SELECT (selection, σ) picks rows, i.e., records, that satisfy a condition. PROJECT picks columns.