INFORMATION MANAGEMENT Unit 2 SO 4 Explain the advantages of using a database approach compared to using traditional file processing; Advantages including speed, efficiency, cost; data quality: completeness, validity, consistency, timeliness and accuracy; data handling, data processing.

What are Traditional File Processing systems? Traditional file based system is basically a file based system, in which we manually handle the database such as updating, inserting, deletion or adding new files to database, etc. Need of external storage No need of highly technical person to handle the database. Provide less security. Redundancy is high Less integrity High complexity in updating of database records Processing speed is low. ADVANTAGESDISADVANTAGES

What is a Database? a structured collection of records or data that is stored in a computer system Records Fields Contains information relating to 1 item of data in a DB This represents 1 unit of information in a database – e.g. Title of DVD, Genre

What is a Database Management System (DBMS)? is computer software designed for the purpose of managing databases based on a variety of data models Advantages Disadvantages Redundancies can be improved! Better services to users Cost of delivering and maintaining the system is lowered Standards can be enforced Security can be improved Integrity can be improved Faster response to query processing Confidentiality, privacy and security Data quality concerns Data integrity concerns Enterprise vulnerability may be higher The cost of using DBMS

Database Views view that the individual user of the database has the information model of the enterprise and contains the view of the whole enterprise without any concern for the physical implementation view about the actual physical storage of data

Role of Database Administrator Deciding and Loading the Database Contents Assisting and Approving Applications and Access Deciding Data Structures Backup and Recovery Monitor Actual Usage

INFORMATION MANAGEMENT Unit 2 SO 5 Describe the different types and organization of files and databases; File types including master and transaction files; file organization including serial, sequential, random or direct, indexed sequential database types including personal, workgroup, department and enterprise databases; database organization including hierarchical, relational, network and object-oriented.

Files Types in Database MASTER FILE A master file or master table contains a group of common records. Item Data, Customer Data, and Supplier Data are examples of tables. TRANSACTION FILE A computer file containing relatively transient data about a particular data processing task Additional Content Check this out!

File Access Methods: Sequential vs. Direct This means...start at the beginning of the file and access each record in turn until the one needed is found. If files are stored on magnetic tape then serial access is the only method of access. Serial Access The computer can calculate (from the key field) where the record is stored in the file, and can then access the record directly from that position. Direct Access can only be used if files are stored on media such as disk, CD, DVD. Direct Access of records will generally be much faster than Serial Access. Direct Access is also known as Random Access. Direct Access Quiz!

File Access Methods: Sequential Access A group of elements (e.g. data in a memory array or a disk file or on a tape) is accessed in a predetermined, ordered sequence Sequential Access

Personal – used for recording self information and for one’s own access. A database created to store phone contacts and addresses and friends would be a good example. Workgroup – used by teams working on tasks that needs access to the same data. Departmental - by a unit in an organization which provides some functional application of the data in the department’s domain Enterprise - Centralized data that is shared by many users throughout the organization

Database Organization NETWORK DATABASE RELATIONAL DATABASE HIERARCHICAL DATABASE OBJECT ORIENTED DATABASE