The entity-relationship model (or ER model) is a way of graphically representing the logical relationships of entities (or objects) in order to create a database. entity type is a collection of entity instances sharing similar properties Strong Entity Vs Weak Entity An entity set that does not have sufficient attributes to form a primary key is termed as a weak entity set. An entity set that has a primary key is termed as strong entity set. A weak entity is existence dependent. That is the
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Computer Science 1K 1.Password Security Password strength is a measure of the effectiveness of a password in resisting guessing and brute-force attacks. In its usual form‚ it estimates how many trials an attacker who does not have direct access to the password would need‚ on average‚ to guess it correctly. The strength of a password is a function of length‚ complexity‚ and unpredictability A password policy is a set of rules designed to enhance computer security by encouraging users to employ
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Oracle Table Triggers Version 11.1 General Data Dictionary Views Related To DDL Triggers trigger$ dba_triggers all_triggers user_triggers System Privileges Related To Table Triggers create trigger create any trigger administer database trigger alter any trigger drop any trigger Table Trigger Firing Options -- before constraints are applied BEFORE INSERT BEFORE UPDATE BEFORE DELETE -- after constraints are applied AFTER INSERT AFTER UPDATE AFTER DELETE Transaction
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Database management systems A database management system (DBMS) consists of software that operates databases‚ providing storage‚ access‚ security‚ backup and other facilities. Database management systems can be categorized according to the database model that they support‚ such as relational or XML‚ the type(s) of computer they support‚ such as a server cluster or a mobile phone‚ the query language(s) that access the database‚ such as SQL or XQuery‚ performance trade-offs‚ such as maximum scale
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Running Head: Database Development Case Study: Database Development Maintenance plans and activities that could be performed in order to improve data quality In order to improve the quality of datasets various activities to be performed like error detection and correlation‚ process design and process control and improvement In error detection method‚ errors are detected by comparing data to a correct baseline and by checking for missing values. By examining time stamp incorrected
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Chapter Three Laws- are rules that mandate or prohibit certain behavior they are drawn from ethics. The key differences between laws and ethics are that laws carry the authority of a governing body‚ and ethics do not. Ethics – define socially acceptable behaviors. Liability- is the legal obligation of an entity that extends beyond criminal or contract law; it includes the legal obligation to make restitution. Restitution- to compensate for wrongs committed. Due care – standards that are met
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Data Management Systems COPYWRITE (2013) BY Robert Ortega MIS405 – 1302A -01: Database Design Instructor: Anita Arceneaux‚ PhD Wednesday‚ May 8‚ 2013; Sunday May 12‚ 2013 Colorado Technical University Virtual Campus Three other Requirements for Database Various other aspects and needed requirements are to be introduced and implemented into Jim and Tim’s new ACCESS™2010® Relational Database Management Systems from concepts‚ theories‚ analysis‚ import/export‚ referential integrity
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What problem would you encounter if you wanted to produce a listing by city? How would you solve this problem by altering the file structure? Some of the project managers are mentioned several times‚ that would cause duplication in the city database. 3. If you wanted to produce a listing of the file contents by last name‚ area code‚ city‚ state‚ or zip code‚ how would you alter the file structure? Divide address capabilities‚ by dividing MANAGER_ADDRESS into its component parts (MGR_STREET
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Lecture-13 Structured Query Language (SQL) Introduction Commercial database systems use more user friendly language to specify the queries. SQL is the most influential commercially marketed product language. Other commercially used languages are QBE‚ Quel‚ and Datalog. Basic Structure The basic structure of an SQL consists of three clauses: select‚ from and where. select: it corresponds to the projection operation of relational algebra. Used to list the attributes desired in the
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elements of a computer based information system is the database. A database is a collection of records or information that is stored in a computer in a structured manner so that information can be stored‚ managed‚ and retrieved. Databases are very useful for manipulating large amounts of data and producing reports and documents. This paper takes a look at the Oracle database system and its usage within my organization. The main objective of a database is to help an organization accomplish its goals
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