2. What is Database Administration ? Database administration' is the process of establishing computerized databases, and insuring their recoverability, integrity, security, availability, reliability, and performance.

3. Introduction to Databases A Database is a collection of a logically related data. And description of this data A database Management System (DBMS) is the software that manages and controls access to the database.

4. Examples of database systems Supermarket products Purchases, checkout bar code reader, a program accesses the database to obtain item description and price, then updates stock balances Credit card details CC reader accesses a database to check the credit present purchases and credit limit. Another program updates balances Holiday and flight details for travel agents Booking arrangements, Travel agent invoicing database. Library database Books’ details, index, borrowers and borrowing details Insurance database University admin and registration database

5. File Based Approach. The flat-file style of database are ideal for small amounts of data that needs to be human readable or edited by hand. Essentially all they are made up of is a set of strings in one or more files that can be parsed to get the information they store; great for storing simple lists and data values, but can get complicated when you try to replicate more complex data structures.

6. Limitations of the File Based Approach Separation and isolation of data An example is a list of course that matches a potential major, since two files have to be accessed: Courses and Major. A program has to be written to create a temporary file that contains the required details Duplication of data - Duplication is wasteful: time, money, and storage space - Duplication leads to loss of data integrity and consistency Data dependence. Incompatibility of files Proliferation (تكاثر، توالد) of application programs which keeps programmers very busy, and reduce the quality of programs

7. Database Approach A database is a shared collection of logically related data (and a description of this data) designed to meet the info needs of an org. It is a large repository of data that is a corporate shared resource. A database is also defined as a self- describing collection of integrated records;

8. The Database Management System (DBMS) A DBMS is a software system that enables users to define, create, and maintain the database and provides controlled access to it. A DBMS provides the following facilities: - Allow users to define a database through DDL, Data Definition Language - Allow user to insert, update, delete, and retrieve data – DML, Data Manipulation Language. - Control access to the database, such as security, integrity, concurrency control, recovery control, and user-accessible catalog.

9. Components of the DBMS Environment Hardware Software Data Procedures People (Users)

10. Roles in the Database Environment Database Administrators (DBA) Database Designers Application Programmers End-Users( Naïve, Sophisticated)

11. 1) Database Administrators (DBA) The database and DBMS are corporate resources and should be managed like any other resources. - Management of data: planning, development, maintenance of standards, policies & procedures, and conceptual/ logical database design. - Design and implementation, security and integrity, maintenance of the operational system ensuring satisfactory performance for the applications and users. 2) Database Designers They are concerned with identifying the data (entities and attributes), the relationships and the constrains. They should know the organization data and its business rules;

12. 3) Application Programmers Application Programs provide the functionality for the end-users, programmers work from specifications produced by the system analysts, they use third generation or fourth generation languages. 4) End-Users They are the clients for the database to serve their information needs. Naïve users They un-aware and do not need to know about the database; they access the database through simple application programs, such as check out or data entry operators. Sophisticated users They are familiar with the structure of the database and the functionality of the DBMS. They use high-level query language, such as SQL.

13. DBA Responsibilities Defining the Schema The DBA defines the schema which contains the structure of the data in the application. The DBA determines what data needs to be present in the system ad how this data has to be represented and organized. Liaising with Users The DBA needs to interact continuously with the users to understand the data in the system and its use. Defining Security & Integrity Checks The DBA finds about the access restrictions to be defined and defines security checks accordingly. Data Integrity checks are also defined by the DBA.

14. DBA Responsibilities (count.) Defining Backup / Recovery Procedures The DBA also defines procedures for backup and recovery. Defining backup procedures includes specifying what data is to backed up, the periodicity of taking backups and also the medium and storage place for the backup data. Monitoring Performance The DBA has to continuously monitor the performance of the queries and take measures to optimize all the queries in the application.

15. DBA Challenges - Ever Changing Technologies - Never ending requests - Urgency of a client’s demands for data - Need to maintain a secure, yet available database environment

16. The History of DBMS GUAM (Generalized Update Access Method), 1960s, by NAA (North American Aviation), the main contractor for Apollo moon landing project. Later IBM joined NAA to develop GUAM to what is known now as IMS (Info Management System) that is based on Hierarchical Structure IDS (Integrated Data Store) of General Electric, based on Network Model IMS and IDS are called first Generation DBMS CODASYL (COnference on DAta SYstems Languages), 1965 Renamed to DBTG (Database Task Group), 1967 DBTG, in their report in 1971, defined the network schema, subschema, and data management language to define the data structure, and manipulate the data. That led to the specification of DDL, DML E F Codd paper on the relational model, 1970 DB2, SQL/DS of IBM in 1980s Oracle 1980s Micro-based DBMS, such as Paradox, dBase, and Access These are called second Generation DBMS The extended relational model, 1976, 1979, and 1990. Object Oriented DBMS and Object-Relational DBMS These are called third Generation DBMS

17. Advantages of DBMSs Control of Data Redundancy Data Consistency Economy of scale Sharing of data Improved data integrity Improved security Improved Backup and Recovery Services Increased Productivity Increased Concurrency Improved Data Accessibility and Responsiveness

18. Disadvantages Complexity Size Cost of DBMSs Additional Hardware Cost Cost of Conversion Performance Higher Impact of a Failure

19. Functions of a DBMS Data storage, retrieval, and update A DBMS must provide users with the ability to store, retrieve, and update data in the database. It should hide the internal physical implementation details from users A user-accessible catalog A DBMS must provide a catalog in which descriptions of data items are stored and which is accessible to users.

20. Functions of a DBMS Transaction Support A DBMS must furnish a mechanism that will ensure that either all updates corresponding to a given transaction are made or that none of them is made. This is to prevent the database being in an inconsistent state. A transaction is a series of actions, carried out by a single user, or a program that access or changes the contents of the database. Concurrency Control Services A DBMS must furnish a mechanism to ensure that the database is updated correctly when multiple users are updating the database concurrently

21. Functions of a DBMS Recovery services A DBMS must furnish a mechanism for recovering the database in the event that the database is damaged in any way. Authorization services A DBMS must furnish a mechanism to ensure that only authorized users can access the database. Support for data communication A DBMS must be capable of integrating with communication software.

22. Functions of a DBMS Integrity services A DBMS must furnish a means to ensure that both the data in the database and changes to the data follow a certain rules. Services to promote data independence A DBMS must include facilities to support the independence of programs from the actual structure of the database. Utility services A DBMS should provide a set of utility services. These are tools to help the DBA to administer the database effectively, such as import facilities, monitor facilities, statistical analysis programs, index reorganization facilities, and many others.

23. The system Catalog It is called sometime DATA DICTIONARY The catalog stores data about the data (meta-data)

24. Relational Database A database file that consists of more than one tables and the relationship can be created between tables on the common field is called relational database. Relationship an association established between common fields (columns) in two tables is called relationship. It is a fundamental concept of relational database. There are three types of relationships. 1. One-to-one relationship 2. One-to-many relationship 3. Many-to-many relationship

25. Types of Relationships One-to-one relationship Two tables are associated in such a way that each record in first table can have only one matching record in second table, and each record in second table can have only one matching record in first table. One-to-many relationship In one-to-many relationship, two tables are associated in such a way that each record in the first table can have many matching records in second table, but a record in second table has only one matching record in first table. Many-to-many relationship In many-to-many relationship, two tables are associated in such a way that each record in the first table can have many matching records in second table, and a record in second table can have many matching records in first table.

26. Database constraints Constraints are declaration of conditions for the database that must remain true. Constraints are used to bind the reading or writing operation from/to the database table. These include tuple-based, attribute base, referential integrity and key constraints. The system examines for the desecration of the constraints on the actions that may cause desecration, and aborts the action accordingly. Constraints can be defined when the table is first created through he "Create Table" statement, of after table creation using "Alter Table" command. Triggers are special kind of inbuilt database constraints.

27. Types of database constraints There are five common types of database constraints:  Not Null  Unique Key  Check  Primary Key  Foreign Key

28. Not Null & Check Constraint

29. Unique Constraint

30. Primary Constraint

31. Foreign Key Constraint

32. Views and their advantages A view is a subset of the database, presented to one user or set of users. The benefits of views are: They reduce complexity by letting users see the data in the way they want They provide security by excluding data that some users should not see They customize the appearance of the database, such as changing attribute names They hide changes in the database and provide consistent view of the database to users. The also provide the program-data independence mentioned earlier