In the context of DBMS, consider the two sets T and S given below.TSI: Logical schemaL: ViewsII: Physical schemaM: File organization and indexesIII: External schemaN: RelationsWhich one of the following is the correct match from T to S ?

The correct match is I - N, II - M, III - L.The three levels of the ANSI-SPARC architecture:the logical (conceptual) schema describes the data as relations, their attributes and constraints (N);the physical schema describes how those relations are stored: file organisation and indexes (M);the external schema is what each user or application sees, defined as views over the relations (L).The options that link the logical schema to views or to file organisation, or the physical schema to views, mix up these levels.

Introduction To Database Questions and Answers

Q: A DBMS is transparent if :

A DBMS is transparent if it keeps hidden a physical structure from user.Transparency in a DBMS means the user works with data without knowing how it is stored: file organisation, indexes, storage devices, and in a distributed database where fragments and copies are kept. This is the physical data independence of the three-schema architecture.The logical structure, the tables, attributes and relationships, is exactly what users and programs work with, so it is not hidden. Hiding sensitive information is a matter of security and authorisation through views and privileges, not of transparency.

Q: If the field size is small, and data to be entered is longer, then :

Part of the data will be cut-off.A field defined with a fixed size, for example a text field of 20 characters, can store only that many characters. If longer data is entered, the extra characters are truncated, or in a strict system the entry is rejected; either way the field does not hold the full value.The program does not freeze, and a fixed-size field does not adjust itself or become flexible. That is why field sizes must be chosen with the longest expected value in mind.

Q: Which amongst the following is an example of object based logical model ?

The object-based logical model is the Entity Relationship Model.Korth and Silberschatz divide data models into object-based logical models, record-based logical models and physical models. Object-based models describe data in terms of objects (entities) and their relationships; the entity-relationship model and the object-oriented model are the standard examples.The network, hierarchical and relational models are record-based logical models: the database is structured as fixed-format records of several types, linked by pointers in the first two and by values in tables in the relational model.

Q: Which of the following is not one of the Codd's rules ?

The one that is not a Codd rule is The structure definition stored in data dictionary should be accessible to all users.Codd's rule 4 (dynamic online catalogue) requires the database's description to be stored like ordinary data and to be queryable by authorised users with the same relational language, not by all users.The other options paraphrase real rules: the information rule (all data in tables), rule 3 (systematic treatment of nulls) and rule 7 (high-level insert, update and delete of sets of rows as well as single rows).

Q: Which of the following statements are true ?(i) Logical independence is the capacity to change the conceptual schema without having to change external schema.(ii) Logical independence is the capacity to change the conceptual schema without having to change internal schema.(iii) Physical independence is the capacity to change the internal schema without having to change conceptual schema.(iv) Physical independence is the capacity to change the conceptual schema without having to change external schema

The true statements are (i) and (iii).In the three-schema architecture, logical data independence is the capacity to change the conceptual schema without having to change the external schemas or application programs (i). Physical data independence is the capacity to change the internal schema without having to change the conceptual schema (iii).Statement (ii) mixes the two levels: changing the conceptual schema does not normally touch the internal schema. Statement (iv) gives physical independence the definition of logical independence.

Q: Which are the two ways in which entities can participate in a relationship?

Correct answer: Total and partialParticipation is total when every entity of the set must take part in the relationship - every loan must have a borrower - and partial when only some need to. In an E-R diagram total participation is drawn with a double line.

Q: Microsoft Access is an enterprise-class database product.

Correct answer: FalseAccess is a personal or workgroup product: it bundles a small DBMS with an application generator in a single file, which suits one user or a handful. Enterprise-class products - SQL Server, DB2, Oracle - run as separate servers and are built for many concurrent users, large volumes and serious administration.

Q: Conceptual design

Correct answer: Involves modelling independent of the DBMSConceptual design captures what the organisation needs to record - entities, attributes and relationships - without reference to any particular product. Choosing tables and types is logical design, and sizing and tuning belong to physical design; keeping them separate is what lets the same conceptual model be implemented on any DBMS.

Which of the following database management systems is developed by Microsoft?

A.Oracle
B.SQL Server
C.MySQL
D.PostgreSQL

Exam Year(s)

DSSSB TGT - 2023,

Answer: B

SQL Server is the database management system developed by Microsoft. Oracle Database is made by Oracle Corporation, MySQL began as an open-source system of a separate company and is now owned by Oracle, and PostgreSQL is developed by an open-source community, so none of those three is a Microsoft product. Its first release was in the late 1980s as a database server, and it is today a common choice for business applications on Windows.

Discuss in Forum

In the context of DBMS, consider the two sets T and S given below.

T	S
I: Logical schema	L: Views
II: Physical schema	M: File organization and indexes
III: External schema	N: Relations

Which one of the following is the correct match from T to S ?

A.I - L, II - M, III - N
B.I - M, II - L, III - N
C.I - N, II - M, III - L
D.I - N, II - L, III - M

Exam Year(s)

GATE CS - 2026,

Answer: C

The correct match is I - N, II - M, III - L.

The three levels of the ANSI-SPARC architecture:

the logical (conceptual) schema describes the data as relations, their attributes and constraints (N);
the physical schema describes how those relations are stored: file organisation and indexes (M);
the external schema is what each user or application sees, defined as views over the relations (L).

The options that link the logical schema to views or to file organisation, or the physical schema to views, mix up these levels.

Discuss in Forum

A DBMS is transparent if :

A.It keeps hidden, a physical structure from user
B.A sensitive information from user cannot be hide
C.It keeps hidden, a logical structure from user
D.A sensitive information from user can be hide

Exam Year(s)

MH SET - 2018, SET Exam - 2018,

Answer: A

A DBMS is transparent if it keeps hidden a physical structure from user.

Transparency in a DBMS means the user works with data without knowing how it is stored: file organisation, indexes, storage devices, and in a distributed database where fragments and copies are kept. This is the physical data independence of the three-schema architecture.

The logical structure, the tables, attributes and relationships, is exactly what users and programs work with, so it is not hidden. Hiding sensitive information is a matter of security and authorisation through views and privileges, not of transparency.

Discuss in Forum

If the field size is small, and data to be entered is longer, then :

A.Part of the data will be cut-off
B.Database program will freeze
C.Field will automatically adjust
D.Field will be flexible

Exam Year(s)

MH SET - 2018, SET Exam - 2018,

Answer: A

Part of the data will be cut-off.

A field defined with a fixed size, for example a text field of 20 characters, can store only that many characters. If longer data is entered, the extra characters are truncated, or in a strict system the entry is rejected; either way the field does not hold the full value.

The program does not freeze, and a fixed-size field does not adjust itself or become flexible. That is why field sizes must be chosen with the longest expected value in mind.

Discuss in Forum

Which amongst the following is an example of object based logical model ?

A.Network Model
B.Hierarchical Model
C.Entity Relationship Model
D.Relational Model

Exam Year(s)

MH SET - 2019, SET Exam - 2019,

Answer: C

The object-based logical model is the Entity Relationship Model.

Korth and Silberschatz divide data models into object-based logical models, record-based logical models and physical models. Object-based models describe data in terms of objects (entities) and their relationships; the entity-relationship model and the object-oriented model are the standard examples.

The network, hierarchical and relational models are record-based logical models: the database is structured as fixed-format records of several types, linked by pointers in the first two and by values in tables in the relational model.

Discuss in Forum

Which of the following is not one of the Codd's rules ?

A.Everything in database must be stored in a table format.
B.Null values in database must be given a systematic and uniform treatment.
C.The structure definition stored in data dictionary should be accessible to all users
D.Database must support insertion, updation and deletion of a single row as also a set of records

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: C

The one that is not a Codd rule is The structure definition stored in data dictionary should be accessible to all users.

Codd's rule 4 (dynamic online catalogue) requires the database's description to be stored like ordinary data and to be queryable by authorised users with the same relational language, not by all users.

The other options paraphrase real rules: the information rule (all data in tables), rule 3 (systematic treatment of nulls) and rule 7 (high-level insert, update and delete of sets of rows as well as single rows).

Discuss in Forum

Which of the following statements are true ?

(i) Logical independence is the capacity to change the conceptual schema without having to change external schema.
(ii) Logical independence is the capacity to change the conceptual schema without having to change internal schema.
(iii) Physical independence is the capacity to change the internal schema without having to change conceptual schema.
(iv) Physical independence is the capacity to change the conceptual schema without having to change external schema

A.(i) and (iii)
B.(i) and (iv)
C.(ii) and (iii)
D.(ii) and (iv)

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: A

The true statements are (i) and (iii).

In the three-schema architecture, logical data independence is the capacity to change the conceptual schema without having to change the external schemas or application programs (i). Physical data independence is the capacity to change the internal schema without having to change the conceptual schema (iii).

Statement (ii) mixes the two levels: changing the conceptual schema does not normally touch the internal schema. Statement (iv) gives physical independence the definition of logical independence.

Discuss in Forum

Which are the two ways in which entities can participate in a relationship?

A.Passive and active
B.Total and partial
C.Simple and Complex
D.All of the above

Answer: B

Correct answer: Total and partial

Participation is total when every entity of the set must take part in the relationship - every loan must have a borrower - and partial when only some need to. In an E-R diagram total participation is drawn with a double line.

Discuss in Forum

Microsoft Access is an enterprise-class database product.

A.True
B.False
C.None of the Above.
D.All of the Above.

Answer: B

Correct answer: False

Access is a personal or workgroup product: it bundles a small DBMS with an application generator in a single file, which suits one user or a handful. Enterprise-class products - SQL Server, DB2, Oracle - run as separate servers and are built for many concurrent users, large volumes and serious administration.

Discuss in Forum

10.

Conceptual design

A.Is a documentation technique.
B.Needs data volume and processing frequencies to determine the size of the database.
C.Involves modelling independent of the DBMS
D.Is designing the relational model.

Answer: C

Correct answer: Involves modelling independent of the DBMS

Conceptual design captures what the organisation needs to record - entities, attributes and relationships - without reference to any particular product. Choosing tables and types is logical design, and sizing and tuning belong to physical design; keeping them separate is what lets the same conceptual model be implemented on any DBMS.

Discuss in Forum

Loading…

Topics

Other Subjects

Tags: Introduction To Database Questions and Answers || Introduction To Database MCQ Questions and Answers || Introduction To Database GK Questions and Answers || Introduction To Database GK MCQ Questions || Introduction To Database Multiple Choice Questions and Answers || Introduction To Database GK || GK on Introduction To Database || Database Questions and Answers || Database MCQ Questions and Answers || Database GK Questions and Answers || GK on Database

Introduction To Database Questions and Answers

Topics

Other Subjects

About Us

Stay informed about all important Dates & Notifications