Object - NCNU Moodle 課程
... • Object-oriented DBMSs deal with data as objects – Object: set of related attributes and actions associated with the attributes – OODBMS: database management system in which data and actions that operate on the data are encapsulated into objects ...
... • Object-oriented DBMSs deal with data as objects – Object: set of related attributes and actions associated with the attributes – OODBMS: database management system in which data and actions that operate on the data are encapsulated into objects ...
mySQL Introduction
... The goal of using foreign keys is that tables can be related without repeating data Note that foreign keys in SQL are used to c heck and enforce referential integrity, not to join tables. If you want to get results from multiple tables from a SELECT stat ement, you do this by performing a join b etw ...
... The goal of using foreign keys is that tables can be related without repeating data Note that foreign keys in SQL are used to c heck and enforce referential integrity, not to join tables. If you want to get results from multiple tables from a SELECT stat ement, you do this by performing a join b etw ...
Irwin/McGraw-Hill
... known as normalization. A table is in normal form if it only contains items that describe the main theme or focus of the table (e.g., customers, sales orders, or inventory) plus any fields needed to link the table with other tables. – Data items (usually key attributes) that are used to combine or l ...
... known as normalization. A table is in normal form if it only contains items that describe the main theme or focus of the table (e.g., customers, sales orders, or inventory) plus any fields needed to link the table with other tables. – Data items (usually key attributes) that are used to combine or l ...
Biometric Databases
... threshold (defined as primary operator) – Score() Returns the degree of match of the input template with a stored template (defined as ancillary to IdentifyMatch operator) • Biometric Vendors define implementations for these operators which are specific to their biometric 14 ...
... threshold (defined as primary operator) – Score() Returns the degree of match of the input template with a stored template (defined as ancillary to IdentifyMatch operator) • Biometric Vendors define implementations for these operators which are specific to their biometric 14 ...
Customer
... – List the number and name of each customer together with the number, last name, and first name of the sales rep who represents the customer. If a customer does not have a Rep., then he/she must not be included. – That is, look for matching RepNum from both tables ...
... – List the number and name of each customer together with the number, last name, and first name of the sales rep who represents the customer. If a customer does not have a Rep., then he/she must not be included. – That is, look for matching RepNum from both tables ...
Hibernatification!
... • Subscription based website which aggregates and organizes state regulatory data and other data in an easy-to-use format. • We employ many different loaders which download data from state agencies and from other sources. • We have a huge database (10 GBs of data at last count?) of information which ...
... • Subscription based website which aggregates and organizes state regulatory data and other data in an easy-to-use format. • We employ many different loaders which download data from state agencies and from other sources. • We have a huge database (10 GBs of data at last count?) of information which ...
SQL – Part II
... – For each sales rep with fewer than four customers, list the rep number, the number of customers assigned to the rep, and the average balance of the rep’s customers. Rename the count of the number of customers and the average of the balances to NumOfCustomers and AverageBalance. – Use of “Having” c ...
... – For each sales rep with fewer than four customers, list the rep number, the number of customers assigned to the rep, and the average balance of the rep’s customers. Rename the count of the number of customers and the average of the balances to NumOfCustomers and AverageBalance. – Use of “Having” c ...
kiferComp_348761_ppt14
... • domain(T) is the set of all objects that conform to type T. Namely: – domain(Integer) = set of all integers, domain(String) = set of all strings, etc. – domain(T), where T is reference type is the extent of T, ie, oids of all objects in class T – domain([A1: T1, …, An: Tn]) is the set of all tuple ...
... • domain(T) is the set of all objects that conform to type T. Namely: – domain(Integer) = set of all integers, domain(String) = set of all strings, etc. – domain(T), where T is reference type is the extent of T, ie, oids of all objects in class T – domain([A1: T1, …, An: Tn]) is the set of all tuple ...
Principles of Information Systems, Ninth Edition
... Works with users to decide the content of the database Works with programmers as they build applications to ensure that their programs comply with database management system standards and conventions ...
... Works with users to decide the content of the database Works with programmers as they build applications to ensure that their programs comply with database management system standards and conventions ...
Web-Based Assesment System - LeMoyne
... Had a web server and network shares but weren’t utilizing either to their potential Had just a few databases, none of which were properly designed, and none which allowed shared access No one in our unit was trained to assist the college and it programs to design databases and collect electronically ...
... Had a web server and network shares but weren’t utilizing either to their potential Had just a few databases, none of which were properly designed, and none which allowed shared access No one in our unit was trained to assist the college and it programs to design databases and collect electronically ...
Transaction Management (cont.)
... been written to secondary storage. • T1 and T6 have to be undone. In absence of any other information, recovery manager has to redo T2, T3, T4, and T5. ...
... been written to secondary storage. • T1 and T6 have to be undone. In absence of any other information, recovery manager has to redo T2, T3, T4, and T5. ...
PHP Database Support
... PHP Database Support (cont'd) • The other way is to access the required database using the PEAR DB library which comes with PHP. – PEAR DB is a database-independent library which hides database specifics allowing the same PHP script to access many DBMSs. – One disadvantage of the PEAR DB approach i ...
... PHP Database Support (cont'd) • The other way is to access the required database using the PEAR DB library which comes with PHP. – PEAR DB is a database-independent library which hides database specifics allowing the same PHP script to access many DBMSs. – One disadvantage of the PEAR DB approach i ...
Lab
... Develop professional applications that are both fast and secure User interface themes, navigational controls, form ...
... Develop professional applications that are both fast and secure User interface themes, navigational controls, form ...
Overview of Database Systems
... A data model hides many low-level details • A schema is a description of a particular collection of data, using a given data model. • The relational model of data is the most widely used model today. ...
... A data model hides many low-level details • A schema is a description of a particular collection of data, using a given data model. • The relational model of data is the most widely used model today. ...
Dell Uses New Database Technology to Consolidate Servers
... Dell, which has a long history of using Microsoft products for its own business, runs many of its applications on Microsoft SQL Server database management software. To enhance the performance and management of its databases, the IT team at Dell decided to implement a beta version of Microsoft SQL Se ...
... Dell, which has a long history of using Microsoft products for its own business, runs many of its applications on Microsoft SQL Server database management software. To enhance the performance and management of its databases, the IT team at Dell decided to implement a beta version of Microsoft SQL Se ...
Views
... Some view updates are not at all possible for translation to relation Instructor (ID, name, department, salary) ...
... Some view updates are not at all possible for translation to relation Instructor (ID, name, department, salary) ...
extended version - Department of Computer Science, University of
... Randomized Approximation Schemes (FPRAS) for model counting of propositional formulas in disjunctive normal form [23, 35]. MystiQ and MayBMS use adaptations of such approximations to probabilistic inference: They repeatedly choose at random a possible world and computes the truth value of query line ...
... Randomized Approximation Schemes (FPRAS) for model counting of propositional formulas in disjunctive normal form [23, 35]. MystiQ and MayBMS use adaptations of such approximations to probabilistic inference: They repeatedly choose at random a possible world and computes the truth value of query line ...
Entity-relationship model - Department of Computer Science
... agreement to assign unique player numbers across all football teams in the world ...
... agreement to assign unique player numbers across all football teams in the world ...
slides19
... 1. ROLAP (Relational OLAP): relational database system tuned for star schemas, e.g., using special index structures such as: ...
... 1. ROLAP (Relational OLAP): relational database system tuned for star schemas, e.g., using special index structures such as: ...
Data Mining
... Generate suitable input format for the clustering tool Define similarity measure Select parameter settings for the chosen clustering algorithm Run clustering algorithm Characterize the computed clusters ...
... Generate suitable input format for the clustering tool Define similarity measure Select parameter settings for the chosen clustering algorithm Run clustering algorithm Characterize the computed clusters ...
Lecture 5: Active Databases
... Whenever some details for an employee are deleted or updated, both the previous and new details are recorded in an audit table to allow tracing the history of changes. An insert operation cannot be recorded with this trigger as old.empno has no value. ...
... Whenever some details for an employee are deleted or updated, both the previous and new details are recorded in an audit table to allow tracing the history of changes. An insert operation cannot be recorded with this trigger as old.empno has no value. ...
Slide 1
... information you divulge – Beware of activities designed to collect information about you – Only supply required information – Look for the opt-out button – Consider using a portable password manager – Be wary of offers for free services – Update antivirus software – Never send personal information i ...
... information you divulge – Beware of activities designed to collect information about you – Only supply required information – Look for the opt-out button – Consider using a portable password manager – Be wary of offers for free services – Update antivirus software – Never send personal information i ...
Relational model
The relational model for database management is an approach to managing data using a structure and language consistent with first-order predicate logic, first described in 1969 by Edgar F. Codd. In the relational model of a database, all data is represented in terms of tuples, grouped into relations. A database organized in terms of the relational model is a relational database.The purpose of the relational model is to provide a declarative method for specifying data and queries: users directly state what information the database contains and what information they want from it, and let the database management system software take care of describing data structures for storing the data and retrieval procedures for answering queries.Most relational databases use the SQL data definition and query language; these systems implement what can be regarded as an engineering approximation to the relational model. A table in an SQL database schema corresponds to a predicate variable; the contents of a table to a relation; key constraints, other constraints, and SQL queries correspond to predicates. However, SQL databases deviate from the relational model in many details, and Codd fiercely argued against deviations that compromise the original principles.