Database Administration and Security Transparencies 1

©Pearson Education 2009 Objectives The distinction between data administration and database administration. The purpose and tasks associated with data administration and database administration. The scope of database security. Why database security is a serious concern for an organization. The type of threats that can affect a database system. How to protect a computer system using computer- based controls. 2

©Pearson Education 2009 Data administration and database administration Data Administrator (DA) and Database Administrator (DBA) are responsible for managing and controlling activities associated with corporate data and corporate database, respectively. DA is more concerned with early stages of lifecycle and DBA is more concerned with later stages. 3

©Pearson Education 2009 Data administration Management and control of corporate data, including: database planning; development and maintenance of standards, policies, and procedures; conceptual and logical database design. 4

©Pearson Education 2009 Data administration tasks 5

©Pearson Education 2009 Database administration Management and control of physical realization of a database system, including: physical database design and implementation; setting security and integrity controls; monitoring system performance; reorganizing the database. 6

©Pearson Education 2009 Database administration tasks 7

©Pearson Education 2009 Comparison of data and database administration 8

©Pearson Education 2009 Database security 9 Mechanisms that protect the database against intentional or accidental threats. Not only apply to the data held in a database. Breaches of security may affect other parts of the system, which may in turn affect the database. Includes hardware, software, people, and data. Growing importance of security is the increasing amounts of crucial corporate data being stored on computer.

©Pearson Education 2009 Examples of threats and possible outcomes 10

©Pearson Education 2009 Summary of threats to computer systems 11

©Pearson Education 2009 Database security Threat is any situation or event, whether intentional or unintentional, that may adversely affect a system and consequently the organization. Outcomes to avoid: theft and fraud, loss of confidentiality (secrecy), loss of privacy, loss of integrity, loss of availability. 12

©Pearson Education 2009 Typical multi-user computer environment 13

©Pearson Education 2009 Database security Computer-based countermeasures include: authorization, views, backup and recovery, integrity, encryption, redundant array of independent disks (RAID). 14

©Pearson Education 2009 Countermeasures - computer-based controls Authorization The granting of a right or privilege that enables a subject to have legitimate access to a database system or a database system’s object. Authentication A mechanism that determines whether a user is, who he or she claims to be. failure. Privilege A right granted by one user to allow another user or group of users access to a database system or an object in the database system. 15

©Pearson Education 2009 Countermeasures - computer-based controls Views A view is a virtual table that does not necessarily exist in the database but can be produced upon request by a particular user, at the time of request. Backup and recovery Process of periodically taking a copy of the database and log file (and possibly programs) onto offline storage media. 16

©Pearson Education 2009 Countermeasures - computer-based controls Journaling Process of keeping and maintaining a log file (or journal) of all changes made to database to enable recovery to be undertaken effectively in the event of failure. Backup window The time period during which the database can be backed up. 17

©Pearson Education 2009 Countermeasures - computer-based controls Integrity Prevents data from becoming invalid, and hence giving misleading or incorrect results. Encryption Encoding the data by a special algorithm that renders the data unreadable by any program without the decryption key. 18

©Pearson Education 2009 Countermeasures - computer-based controls RAID A set or array of physical disk drives that appear to the database user (and programs) as if they form one large physical storage. Striping: Spreading data blocks across multiple disks Parity: Additional data used to re-create missing data Hardware that the DBMS runs on must be fault- tolerant, meaning that the DBMS should continue to operate even if one of the hardware components fails. RAID Levels Level 0: Striping only. No redundancy Level 1: Mirroring. Multiple copies of data Level 3: Single disk parity Level 5: Distributed Parity 19

©Pearson Education 2009 Network security architecture three tier database system architecture 20

©Pearson Education 2009 Countermeasures - network security Network security is the protect of servers from intruders. Firewall is a server or router with two or more network interfaces and special software that filters or selectively blocks messages traveling between networks. De-Militarized Zone (DMZ) is a special, restricted network that is established between two firewalls. 21