logging in or signing up DATA BASE SCHEMAS Thekrishnavn Download Post to : URL : Related Presentations : Let's Connect Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Copy embed code: Embed: Flash iPad Dynamic Copy Does not support media & animations Automatically changes to Flash or non-Flash embed WordPress Embed Customize Embed URL: Copy Thumbnail: Copy The presentation is successfully added In Your Favorites. Views: 2132 Category: Education License: All Rights Reserved Like it (4) Dislike it (0) Added: November 18, 2009 This Presentation is Public Favorites: 1 Presentation Description No description available. Comments Posting comment... By: Manjujeevan (41 month(s) ago) Please allow to download Saving..... Post Reply Close Saving..... Edit Comment Close By: artiattri (41 month(s) ago) plz allow me to download this ppt Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript DATA BASE SCHEMAS : DATA BASE SCHEMAS Slide 2: Data base system:-A database is an organized pool of logically-related data. Data is stored within the data structures of the database. Data Base Management System:-is a set of computer programs that controls the creation, maintenance, and the use of the database in a computer platform or of an organization and its end users. Slide 3: Data Dictionary:- It is a centralized repository of information about data such as meaning, relationships to other data, origin, usage, and format. It is a document describing a database or collection of databases DATA BASE SCHEMA- Definition : DATA BASE SCHEMA- Definition A database schema is a collection of meta-data that describes the relations in a database A schema can be simply described as the "layout" of a database or the blueprint that outlines the way data is organized into tables. The schema of a database system is its structure described in a formal language supported by the database management system (DBMS) Slide 5: In a relational database, the schema defines the tables, the fields, relationships, views, indexes, packages, procedures, functions, queues, triggers, types, sequences, materialized views, synonyms, database links, directories, Java, XML schemas, and other elements. Schemas are generally stored in a data dictionary Levels of database schema : Levels of database schema Conceptual schema Logical schema Physical schema Schema object Conceptual schema : Conceptual schema A conceptual schema or conceptual data model is a map of concepts and their relationships. It describes the things of significance to an organization (entity classes), about which it is inclined to collect information, and characteristics of (attributes) and associations between pairs of those things of significance (relationships). Logical schema : Logical schema A Logical Schema is a data model of a specific problem domain expressed in terms of a particular data management technology. It is a map of entities and their attributes and relations Without being specific to a particular database management product, it is in terms of either relational tables and columns, object-oriented classes, or XML tags. Physical schema : Physical schema It is a particular implementation of a logical schema It is a term used in relation to data management how physically data would be stored on disk drives. That is the domain of the physical schema. Schema object : Schema object It is a logical data storage structure A schema is a collection of schema objects. Examples of schema objects include tables, views, sequences, synonyms, indexes, clusters, database links, snapshots, procedures, functions, and packages Oracle stores a schema object logically within a table space of the database. The data of each object is physically contained in one or more of the table space’s data files. THANK YOU KRISHNA.V.N : THANK YOU KRISHNA.V.N You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.