Data Storage analysis and design, , wixom, and M. Roth © 2015 John Wiley & Sons, Inc. All rights 1Learning ObjectivesBecome familiar with several file and database formatsDescribe several goals of data storageBe able to revise a logical ERD into a physical ERDBe able to optimize a relational database for data storage and data accessBecome familiar with indexesBe able to estimate the size of a database © 2015 John Wiley & Sons, Inc. All rights 2Key storage function: how data is stored and handled by run the systemData storage design:.◦ select the data storage format;.◦ convert the logical data model into a physical data model to reflect. implementation decisions;.◦ ensure that DFDs and ERDs balance; and.◦ design the selected data storage format to optimize its processing. efficiency © 2015 John Wiley & Sons, Inc. All rights 3Data Storage the best storage option. © 2015 John Wiley & Sons, Inc. All rights 4DATA STORAGE FORMATSTypes of data storage formats:.◦ Files: electronic lists of data, optimized to perform a particular transaction◦ Database: a collection of groupings of information that are related to each. other in some wayDatabase Management System (DBMS):.software that creates and manipulates © 2015 John Wiley & Sons, Inc. All rights 5FilesData file: an electronic list of is formatted for a organization is typicalRecord associations with other by pointersAlso called linked lists because of the records are linked together © 2015 John Wiley & Sons, Inc. All rights 6Types of FilesMaster files – store core information that to the applicationLook-up files – contain static valuesTransaction files – store information be used to update a master fileAudit files – record “before” and “after”.images of data as the data is alteredHistory files (or archive files) – store . © 2015 John Wiley & Sons, Inc. All rights . © 2015 John Wiley & Sons, Inc. All rights 8DatabasesThere are many types of databases:.◦ Legacy database.◦ Relational database.◦ Object database.◦ Multidimensional database.◦ NoSQL database. © 2015 John Wiley & Sons, Inc. All rights 9Legacy DatabasesDatabases which are based on ; seldom used to develop major types:.◦ Hierarchical databases use hierarchies, or inverted trees, to represent. relationships◦ Network databases are collections of records that are related to each other. through pointers © 2015 John Wiley & Sons, Inc. All rights 10Relational DatabasesThe most popular kind of database development todayBased on collections of tables, each has a primary keyTables are related to each other by the primary key from one the related table as a foreign key © 2015 John Wiley & Sons, Inc. All rights 11Relational Databases, con’ relational database (RDBMS) support ; ensures that values linking together are valid and Query Language (SQL) is language for accessing the data tables © 2015 John Wiley & Sons, Inc. All rights . © 2015 John Wiley & Sons, Inc. All rights 13Object DatabasesBased on object orientation: that all be treated as objects that have (attributes) and processes (
