Week 5 Flashcards Preview

Database Systems > Week 5 > Flashcards

Flashcards in Week 5 Deck (14):
1

Database security involves measures to avoid?

1. Theft and fraud
2. loss of confidentiality
3. loss of privacy
4. loss of integrity
5. loss of availability

2

What is Threat?

Threat is any situation or event, whether intentional or unintentional, that will adversely affect a system and consequently an organization.

3

2 jenis approach untuk access controls dalam DBMS?

1. DAC (Discretionary Access Control)
Each user is given appropriate access rights or privileges on specific database objects through the GRANT and REVOKE commands. GRANT command gives privileges to users and REVOKE command takes away privileges.

2. MAC (Mandatory Access Control)
This approach, each database object is assigned a SECURITY CLASS and each user is assigned a CLEARANCE for a security class, and RULES are imposed on reading and writing of database objects by users.

4

What is View?

A view is the dynamic result of one or more relational operations operating on the base relations to produce another relation.

5

What is Backup?

The process of periodically copying of the database and log file (and possibly programs) to offline storage media.

6

What is Journaling?

The process of keeping and maintaining a log file ( or journal) of all changes made to the database to enable recovery to be undertaken effectively in the event of a failure.

7

What is Integrity?

Prevents data from becoming invalid, and hence giving misleading or incorrect results.

8

What is Encryption?

The encoding of the data by a special algorithm that renders the data unreadable by any program without the decryption key.

9

RAID (Redundant Array of Independent Disks)

RAID works on having a large disk array comprising an arrangement of several independent disks that are organized to improve reliability and at the same time increase performance.

Levels:
RAID 0 Nonredundant
RAID 1 Mirrored
RAID 0+1 Nonredundant and Mirrored
RAID 2 Memory-Style Error-Correcting Codes RAID 3 Bit-Interleaved Parity
RAID 4 Block-Interleaved Parity
RAID 5 Block-Interleaved Distributed Parity
RAID 6 P+Q Redundancy

10

What is Relation Schema?

relation schema is named relation defined by a set of attribute and domain name pairs

11

Relational database schema?

set of relation schemas, each with a distinct name.

12

5 relational keys?

1. superkey
an attribute that uniquely identifies a tuple within a relation
2. candidate key
superkey such that no proper subset is a superkey within the relation.
3. primary key
candidate key selected to identify tuples uniquely within relation.
4. alternate key
candidate key that are not selected to be primary key
5. foreign key
attribute within one relation that matches candidate key of some relation

13

4 integrity constraints?

1. Null
2. Entity integrity
3. referential integrity
4. general constraint

14

6 jenis privileges dalam DAC (Discretionary Access Control)?

1. SELECT
2. INSERT
3. UPDATE
4. DELETE
5. REFERENCES
6. USAGE