Saturday, February 1, 2020

NORMALIZATION AND SQL DDL STATEMENTS Essay Example | Topics and Well Written Essays - 500 words

NORMALIZATION AND SQL DDL STATEMENTS - Essay Example Atomicity ensures that no incomplete transactions are ever executed by the system which ensures the state of data always remains stable despite any hardware/software failures. Consistency ensures that only those transactions will execute that do not violate any of the database consistency rules which ensures data remains valid. Isolation ensures uninterrupted single transaction processing e.g. the concurrent transaction requests are handled serially i.e. one transaction at a time. Durability ensures that transactions are logged and therefore transactions can be rolled back at any time. Database normalization is a set of guidelines that helps in organizing data efficiently which improves the overall performance of a DBMS. It helps remove data redundancy (does not allow duplicate data storage in multiple tables) which in turn reduces the space consumed by database. Furthermore, it improves data consistency by allowing only sensible and logical data dependencies between tables (e.g. a table stores only data that is related). There are five normal forms of database; 1NF, 2NF, 3NF, BCNF and 4NF. Mostly, normalization till the third form is enough for most database system applications. 1NF helps eliminate duplicate column from a table and identifies unique column(s) i.e. through primary key. 2NF separates data subsets into separate tables forming foreign keys. And 3NF ensures all columns in a table are dependent only on the primary key. The exercise helped in understanding the concept of ACID model and offered a hands-on approach to designing and optimizing a database design. It helped in practicing the application of the most widely used normalization guidelines on a previously formed database model. Furthermore, it also helped practice the DDL statements involved in the actual creation of a database application in

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