Database Concepts
- 2. CONTENTS 1 2 3 4 Concept of Data, Record and File. Type of Data and Data Structure Data File handling and operations – Data storage and retrieval Data Operations – Algorithms: Sorting , Merging, Joining & Bifurcation Data Base Concept and Operation on Data Base.
- 4. A database is a base collection of data. A database is a collection of related data that is stored in a system. This data is stored in such a way that it can be updated, modified or retrieved as and when required. A file is a collection of related records. DATABASE
- 5. BASICS OF DATABASE FieldData Record A bit is a binary digit. It is either 0 or 1. One byte is equal to 8 bits Raw facts that form a logical meaning are called Data. Data can be numeric (1, 2, 3…). Alpha (a, b, c…) or Alphanumeric such as a combination of both numbers and alphabets(31st March) Field is a data item that contains characters which have specific meaning such as Name of student, Address, Specialization etc. A record is a collection of one or more fields that represents the information about a person, place or thing. For example, a record of a student will contain his name, age, gender, class section, course, etc. Bit & Byte
- 6. Characteristics of a Database Data independence and Data abstraction Self describing nature of a database system Support of multiple views of data Data sharing The database system contains not only the database itself but also information about the database such as type of file, storage format, etc. Such information about data is called metadata This refers to the ability of the database system to add, delete, update or modify any record in the database without affecting the already stored program Since a database system supports multiple users to access the data, update or modify it at the same time, it has to follow certain redundancy control measures to avoid concurrency or duplicity of information A database might have multiple users accessing the same data at the same time. Thus it supports multiple views and various facilities giving different perspective to the users.
- 7. DATABASE TYPE A database data type refers to the format of data storage that can hold a distinct type or range of values. When computer programs store data in variables, each variable must be designated a distinct data type. Some common data types are as follows: integers, characters, strings, floating point numbers and arrays. More specific data types are as follows: varchar (variable character) formats, Boolean values, dates and timestamps.
- 8. Data Base Management (DBM) is defined as a software or hardware system that interfaces between the data bases on a system and users and programs to provide for addition, deletion, modification or retrieval of data elements, records and files by logical reference to them. Functions of DBMS: 1. It Organizes Data 2. It integrates Data 3. It Separates Data 4. It Controls Data 5. It Retrieves Data 6. It Protects Data.
- 9. DBMS FUNCTIONS Data Dictionary Management Data Storage Management Data Transportation & Presentation Security Management Multiuser access control Backup & Recovery Management Data Integrity Management Data Access Languages Database Communication
- 10. DATA STRUCTURE • A data structure is a collection of different forms and different types of data that has a set of specific operations that can be performed. • It is a collection of data types. • It is a way of organizing the items in terms of memory, and also the way of accessing each item through some defined logic. • Some examples of data structures are stacks, queues, linked lists, binary tree and many more
- 11. Differences between data type and data structure Data Type is the kind or form of a variable which is being used throughout the program. It defines that the particular variable will a ssign the values of the given data type only. Implementation through Data Types is a f orm of abstract implementation. Can hold values and not data, so it is data less. Values can directly be assigned to the data type variables. No problem of time complexity. Examples: int, float, double Data Type Data Structure is the collection of d ifferent kinds of data. That entire data c an be represented using an object and c an be used throughout the entire pr ogram. Implementation through Data Structures i s called concrete implementation. Can hold different kind and types of data within one single object. The data is assigned to the data structure object using some set of algorithms and operations like push, pop and so on. Time complexity comes into play when working with data structures. Examples: stacks, queues, tree Data Structure
- 12. Thank You Dr.Saradha A Assistant Professor Department of Economics Ethiraj College for Women Chennai