After studying this chapter, you should be able to: Explain the importance and advantages of databases, as well as the difference between database systems and file-based legacy systems; explain the difference between logical and physical views of a database; explain fundamental concepts of database systems such as DBMS, schemas, the data dictionary, and DBMS languages;. | Relational Databases Chapter 4 4-1 Learning Objectives Explain the importance and advantages of databases, as well as the difference between database and file-based legacy systems. Explain the difference between logical and physical views of a database. Explain fundamental concepts of database systems such as DBMS, schemas, the data dictionary, and DBMS languages. Describe what a relational database is and how it organizes data. Create a set of well-structured tables to properly store data in a relational database. Perform simple queries using the Microsoft Access database. 4-2 What Is a Database? Efficiently and centrally coordinates information for a related group of files A file is a related group of records A record is a related group of fields A field is a specific attribute of interest for the entity (record) 4-3 Advantages of Databases Data is integrated and easy to share Minimize data redundancy Data is independent of the programs that use the data Data is easily accessed for | Relational Databases Chapter 4 4-1 Learning Objectives Explain the importance and advantages of databases, as well as the difference between database and file-based legacy systems. Explain the difference between logical and physical views of a database. Explain fundamental concepts of database systems such as DBMS, schemas, the data dictionary, and DBMS languages. Describe what a relational database is and how it organizes data. Create a set of well-structured tables to properly store data in a relational database. Perform simple queries using the Microsoft Access database. 4-2 What Is a Database? Efficiently and centrally coordinates information for a related group of files A file is a related group of records A record is a related group of fields A field is a specific attribute of interest for the entity (record) 4-3 Advantages of Databases Data is integrated and easy to share Minimize data redundancy Data is independent of the programs that use the data Data is easily accessed for reporting and cross-functional analysis 4-4 Database Users and Designers Different users of the database information are at an external level of the database. These users have logical views of the data. At an internal level of the database is the physical view of the data which is how the data is actually physically stored in the system. Designers of a database need to understand user’s needs and the conceptual level of the entire database as well as the physical view. 4-5 Database Design To design a database, you need to have a conceptual view of the entire database. The conceptual view illustrates the different files and relationships between the files. The data dictionary is a “blueprint” of the structure of the database and includes data elements, field types, programs that use the data element, outputs, and so on. 4-6 DBMS Languages Data Definition Language (DDL) Builds the data dictionary Creates the database Describes logical views for each user Specifies record or field .
