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Database management system introduction.pptx
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- 2. Objectives •The main objectivesof database management system are • Data availability, • Data integrity, • Data security, and • Data independence
- 3. Data Availability • Thedata which we created will be available to the wide variety of users can access the date easily in a meaningful format Client1 Client2 Client3
- 4. Data Integrity • thecorrectness of the data in the database • Data can be accessed by any user accurately • Data must consistent to access with any type of application • Data must access without any problem.
- 5. Data Security • onlyauthorized users can access the data. • Data security can be enforced by passwords. • If multiple users accessing same data, DBMS must not allow conflict changes
- 6. Data Independence • Oneof the main objectives of DBMS is to facilitate sharing of a database by current and future applications. • There are two different data independence • Logical Data Independence • Data can be modified without changing Physical Schema • Physical Data Independence • Data can be changed with change in logical schema
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- 8. Introduction • In recentyears, two approaches to DBMS are more popular, which are • Object-Oriented DBMS (OODBMS) • Object Relational DBMS (ORDBMS).
- 9. The sequential orderof the development of DBMS is as follows: • Flat files – 1960s–1980s • Hierarchical – 1970s–1990s • Network – 1970s–1990s • Relational – 1980s–present • Object-oriented – 1990s–present • Object-relational – 1990s–present • Data warehousing – 1980s–present • Web-enabled – 1990s–present
- 10. • Early 1960s. •Charles Bachman created the first general purpose DBMS Integrated Data Store. • It created the basis for the network model which was standardized by CODASYL (Conference on Data System Language). • Late 1960s: • IBM developed the Information Management System (IMS). • IMS used an alternate model, called the Hierarchical Data Model. • In 1970: • Edgar Codd, from IBM created the Relational Data Model. • In 1981: • Codd received the Turing Award for his contributions to database theory. • Codd Passed away in April 2003.
- 11. • In 1976: •Peter Chen presented Entity-Relationship model, which is widely used in database design. • In 1980: • SQL developed by IBM, became the standard query language for databases. SQL was standardized by ISO. • • In 1980s and 1990s: • IBM, Oracle, Informix and others developed powerful DBMS.
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- 13. • Database managementsystems can be classified based on several criteria, such as the data model, user numbers and database distribution • Based on the data model • Based on the number of users • Based on the sites over which network is distributed • Based on usage
- 14. Based on thedata model Relational database • They are table oriented which means data is stored in different tables, each has the key field whose task is to identify each row. Object oriented database The information here is in the form of the object as used in object oriented programming. It adds the database functionality to object programming languages.
- 15. Hierarchical database • Theinformation is represented in the form of parent child releationship • It is mainly used in mainframe comuputers Network database Mainly used on a large digital computers. If there are more connections, then this database is efficient.
- 16. Based on thenumber of users Single user • As the name itself indicates it can support only one user at a time. • It is mostly used with the personal computers. • The user may design, maintain and write the database programs. Multiple users • It supports multiple users concurrently. • Data can be both integrated and shared, a database should be integrated when the same information is not need be recorded in two places.
- 17. Based on thesites over which network is distributed Centralized database system • The DBMS and database are stored at the single site that is used by several other systems too. • We can simply say that data here is maintained on the centralized server. Parallel network database system • This system has the advantage of improving processing input and output speeds. • Majorly used in the applications that have query to larger database. Distributed database system In this data and the DBMS software are distributed over several sites but connected to the single computer.
- 18. Based on usage OnlineTransaction Processing(OLTP) DBMS • They manage the operational data. • Database server must be able to process lots of simple transactions per unit of time. Online Analytical Processing(OLAP) DBMS • They use the operational data for tactical and strategical decision making. • They have limited users deal with huge amount of data, complex queries.
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- 20. Database • The databaseconsists of logically related data stored in a single data storage area • It is possible to remove most of the file system’s problems
- 21. Database Management System •It is a collection of software programs used to create and manipulate data stored in database. • The database system is composed of the five major ports • Hardware • Software • People • Procedures • Data
- 23. Hardware • Hardware isphysical components connect to computer • DBMS required basic hardware components such as • Hard disk to store data in database • Input devices to provide instructions • Output devices to display results • RAM to hold data temporarily • Like above there are different kind of hardware required to use DBMS.
- 24. Software • It isthe program which controls everything • DBMS is software wrapped around the database • It provides us with an easy-to-use interface to store, access and update data. • DBMS software converts database access language into database commands to access database
- 25. Data • Data isthat resource, for which DBMS was designed • DBMS was created to store and utilize data. • Database stores users data and metadata. • Data is collection of raw (unstructured) information • Metadata is data about data, i.e., where data is stored, what is size of data etc.
- 26. Procedures • general instructionsto use a database management system • That includes • To setup and install a DBMS • To Login and logout of DBMS software • To manage database • To take backups • To generating reports , etc.
- 27. Users: • users whointeract with database system • Database Administrator • Database Administrator is the one who manages the complete database management system • DBA takes care of • the security of the DBMS • it's availability • managing the license keys • managing user accounts and access, etc. • Application programmer or software developer • This user group is involved in developing and designing the parts of DBMS. • End users • End users are the one who store, retrieve, update and delete data.
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- 29. What is DataModel? • the logical design and structure of a database • defines how data will be stored, accessed and updated in a DBMS • While the Relational Model is the most widely used database model,
- 30. Types of DataModels • Database Evolution changes the style of data stored in database. • There are four different data models • Hierarchical Data model • Network Data Model • Entity relationship data model • Relational data model • Object Oriented
- 31. Hierarchical Model • organizesdata into a tree-like-structure (upside down tree) • Hierarchy starts with single root expands like a tree, adding child nodes to the parent nodes. • In this model child node will only have a single parent node.
- 33. Advantages are. 1.It promotesdata sharing. 2.Maintains parent child relationship 3.Database security is provided and enforced by DBMS 4.Provides data integrity. 5.It is efficient with one to many relationships. Disadvantages are. 1.Requires knowledge of physical data storage 2.Requires knowledge of hierarchical path 3.Changes of structures will require changes in all applications 4.No support of DDL or DML
- 34. Network model • Itis extension of the Hierarchical model. • data is organized more like a graph • One child can have multiple parent nodes • Data has more relationships established in this model • Used for many to many data relationships • Most widely used model before Relational model introduced.
- 36. Advantages are. 1.It promotesdata sharing. 2.Parent/Child relationship promotes conceptual simplicity. 3.Database security is provided and enforced by DBMS 4.Parent/Child relationship promotes data integrity. 5.It is efficient with M: M relationships. Disadvantages are. 1.Requires knowledge of physical data storage 2.Changes of structures will require changes in all applications 3.Implementation limitations are there
- 37. Entity relationship model •It was introduced in the year 1976, by peter chen • graphical representation of entities and their relationships in a database structure. • This model provides good structured database design • It is represented using ER diagrams • Object is defined as Entity and it’s characteristics are defined as attributes
- 39. Advantages • Straight-forward representationof relationships • easy convert ER Model to any other model • Provides Graphical representation of Database
- 40. Dis-Advantages • There isno Industrial Standards • It is not suitable for Low level design.
- 41. Relational Data model •Introduced by EF CODD in the year 1970 • It was the most widely used to data model to create RDBMS applications • Data is organized in the form of tables • Relationships are maintained by storing common field • In this model tables are known as “Relations”
- 43. Advantages • Relational modelis very simple than Hierarchical and Network model. • Easy to user because of tables having rows and columns. • Faster to access data stored in database • It follows Constraints and Other rules to manage database and data integrity
- 44. Disadvantages •It becomes morecomplex when data grows in database. •When database become complex , data sharing is not possible.
- 45. Object Oriented Model •In this model , database is designed with group of objects. • Objects contains Data and Behaviors. • This models helps us to create OODBMS(Object Oriented Database Management System) • OOD will allows us to communicate with object Oriented languages.
- 46. Object1 Object2 Object3 Data members Datamembers Data members Methods Methods Methods
- 47. Advantages: • It ismainly used to complex datatypes, such as images,videos, audio,etc. • Flexible to access data. • Able to store large amount of data • Easily integrated into web and other applications
- 48. Disadvantages •Data accessing slowerthan relational model •Because of Complex data, degrade performance of database.