Overview of Relational Databases
... database objects (e.g., table names, field names). It is usually best to assume that they are case preserving, but not case sensitive. Also, avoid special characters and space in database object names. 6. Most relational databases use the same SQL language. When you get to more advanced features, th ...
... database objects (e.g., table names, field names). It is usually best to assume that they are case preserving, but not case sensitive. Also, avoid special characters and space in database object names. 6. Most relational databases use the same SQL language. When you get to more advanced features, th ...
File
... 40. What is Functional Dependency? A Functional dependency is denoted by X Y between two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuple that can form a relation state r of R. The constraint is for any two tuples t1 and t2 in r if t1[X] = t2[X] then they ...
... 40. What is Functional Dependency? A Functional dependency is denoted by X Y between two sets of attributes X and Y that are subsets of R specifies a constraint on the possible tuple that can form a relation state r of R. The constraint is for any two tuples t1 and t2 in r if t1[X] = t2[X] then they ...
Chapter 3 Notes
... • Attribute A1 is a foreign key of R1 referring to attribute A2 in R2, if whenever there is a value v of A1, there is a tuple of R2 in which A2 has value v, and A2 is a key of R2 – This is a special case of referential integrity: A2 must be a candidate key of R2 (e.g., CrsCode is a key of Course in ...
... • Attribute A1 is a foreign key of R1 referring to attribute A2 in R2, if whenever there is a value v of A1, there is a tuple of R2 in which A2 has value v, and A2 is a key of R2 – This is a special case of referential integrity: A2 must be a candidate key of R2 (e.g., CrsCode is a key of Course in ...
chapter 3 ppt
... A collection of information that you organize and access according to the logical structure of that information. uses a series of logically related two-dimensional tables (called relations) or files to store information in the form of a database. ...
... A collection of information that you organize and access according to the logical structure of that information. uses a series of logically related two-dimensional tables (called relations) or files to store information in the form of a database. ...
Data Mining – Quick Start - ICONICS, Inc.
... Right-click on your database connection Northwind and select New Datasource. Give the Datasource a name (i.e. ReadOneCell). You may also enter a description if you wish. We will use this data source to read one single cell in the database. Select Database Table under Specify Dataset. You can alter ...
... Right-click on your database connection Northwind and select New Datasource. Give the Datasource a name (i.e. ReadOneCell). You may also enter a description if you wish. We will use this data source to read one single cell in the database. Select Database Table under Specify Dataset. You can alter ...
PL/SQL Enhancements in Oracle Database 11g
... workarounds) and that make programming more comfortable ...
... workarounds) and that make programming more comfortable ...
PHP and MySQL
... CREATE TABLE employee ( id INT NOT NULL AUTO_INCREMENT, // id name VARCHAR(11), INDEX name_ix(name) ); ...
... CREATE TABLE employee ( id INT NOT NULL AUTO_INCREMENT, // id name VARCHAR(11), INDEX name_ix(name) ); ...
Introduction to Computer and Communications Security
... Apply Principle of Least Privilege! Limit Read access, tables/views user can query Commands (are updates/inserts ok?) ...
... Apply Principle of Least Privilege! Limit Read access, tables/views user can query Commands (are updates/inserts ok?) ...
PPT
... all privileges: used as a short form for all the allowable privileges index - allows creation and deletion of indices resources - allows creation of new relations alteration - allows addition or deletion of attributes in a relation drop - allows deletion of relations Database System Concep ...
... all privileges: used as a short form for all the allowable privileges index - allows creation and deletion of indices resources - allows creation of new relations alteration - allows addition or deletion of attributes in a relation drop - allows deletion of relations Database System Concep ...
Dynamic Query Forms for Database Queries
... DBPedia, typically have thousands of structured web entities [4] [2]. Therefore, it is difficult to design a set of static query forms to satisfy various ad-hoc database queries on those complex databases. ...
... DBPedia, typically have thousands of structured web entities [4] [2]. Therefore, it is difficult to design a set of static query forms to satisfy various ad-hoc database queries on those complex databases. ...
Discovery and Maintenance of Functional Dependencies by Independencies
... to our approachin orderto discover functional dependencies, there are similar ones by Mannila and R/iih~i (Mannila & Riiildi 199l), Dehaspe et al. (Dehaspe, Laer, & Raedt 1994), Savnik and Flach (Savnik & Flach 1993), and Schlimmer (Schlimmer 1993). Mannila and Riiih~i have investigated the problem ...
... to our approachin orderto discover functional dependencies, there are similar ones by Mannila and R/iih~i (Mannila & Riiildi 199l), Dehaspe et al. (Dehaspe, Laer, & Raedt 1994), Savnik and Flach (Savnik & Flach 1993), and Schlimmer (Schlimmer 1993). Mannila and Riiih~i have investigated the problem ...
Data Modeling Overview
... noun is a candidate for an entity Every entity should be relevant to the problem If an object has only one property of importance, then it should be considered an attribute of another entity If an object has only one data instance (1 row) then do not model as an entity If an object needs a u ...
... noun is a candidate for an entity Every entity should be relevant to the problem If an object has only one property of importance, then it should be considered an attribute of another entity If an object has only one data instance (1 row) then do not model as an entity If an object needs a u ...
Relational Databases for the Business Analyst
... The RDBMS and its role in the enterprise Data discovery and finding it faster A SQL overview and the Procedural Languages found in the RDBMS Best practices in SQL and understanding SQL Performance at a high level ETL and how is it used in the enterprise today OLTP v Decision Support Systems How to e ...
... The RDBMS and its role in the enterprise Data discovery and finding it faster A SQL overview and the Procedural Languages found in the RDBMS Best practices in SQL and understanding SQL Performance at a high level ETL and how is it used in the enterprise today OLTP v Decision Support Systems How to e ...
Movie
... Using two INSERT statements, store in the database the fact that PC model 1100 is made by manufacturer C, has speed 1800, RAM 256, hard disk 80, a 20x DVD, and sells for $2499. Insert the facts that for every PC there is a laptop with the same manufacturer, speed, RAM and hard disk, a 15-inch screen ...
... Using two INSERT statements, store in the database the fact that PC model 1100 is made by manufacturer C, has speed 1800, RAM 256, hard disk 80, a 20x DVD, and sells for $2499. Insert the facts that for every PC there is a laptop with the same manufacturer, speed, RAM and hard disk, a 15-inch screen ...
Notes (Wrapup)
... Data Retrieval How to ask questions of the database How to answer those questions Data Storage How/where to store data, how to access it Data Integrity ...
... Data Retrieval How to ask questions of the database How to answer those questions Data Storage How/where to store data, how to access it Data Integrity ...
lis651p05a-02
... • CREATE allows users to create new databases or tables. If a specific table or database is mentioned in the GRANT statement, users can only create that database or table, which will mean that they have to drop it first. • USAGE allows users nothing. This is a useful point to start with if you just ...
... • CREATE allows users to create new databases or tables. If a specific table or database is mentioned in the GRANT statement, users can only create that database or table, which will mean that they have to drop it first. • USAGE allows users nothing. This is a useful point to start with if you just ...
Chapter 1
... provides description of data Data: Known facts that can be recorded and have an implicit meaning. Database Management System (DBMS): A software system that enables users to define, create, maintain, and control access to the database. ...
... provides description of data Data: Known facts that can be recorded and have an implicit meaning. Database Management System (DBMS): A software system that enables users to define, create, maintain, and control access to the database. ...
Week7
... Authors (Name, Email, Paper_ID, …) Underlined attributes are primary keys. Attributes in italics are foreign keys. ...
... Authors (Name, Email, Paper_ID, …) Underlined attributes are primary keys. Attributes in italics are foreign keys. ...
Lecture 1- Query Processing
... Can implement selections of the form AV (r) or A V(r) by using a linear file scan, or by using indices in the following ways: A5 (primary index, comparison). (Relation is sorted on A) For A V(r) use index to find first tuple v and scan relation sequentially from there For AV (r) just ...
... Can implement selections of the form AV (r) or A V(r) by using a linear file scan, or by using indices in the following ways: A5 (primary index, comparison). (Relation is sorted on A) For A V(r) use index to find first tuple v and scan relation sequentially from there For AV (r) just ...
Database Systems: Design, Implementation, and Management Ninth
... • A job – such as accountant or sales representative -- can be assigned to many employees. (For example, one would reasonably assume that a store can have more than one sales representative. Therefore, the job title “Sales Representative” can be assigned to more than one employee at a time.) Each em ...
... • A job – such as accountant or sales representative -- can be assigned to many employees. (For example, one would reasonably assume that a store can have more than one sales representative. Therefore, the job title “Sales Representative” can be assigned to more than one employee at a time.) Each em ...
The Relational Model
... A set of fields is a key for a relation if : 1. No two distinct tuples can have same values in all key fields, and 2. This is not true for any subset of the key. Part 2 false? A superkey. If there’s >1 key for a relation, one of the keys is chosen (by DBA) to be the primary key. ...
... A set of fields is a key for a relation if : 1. No two distinct tuples can have same values in all key fields, and 2. This is not true for any subset of the key. Part 2 false? A superkey. If there’s >1 key for a relation, one of the keys is chosen (by DBA) to be the primary key. ...
HQL
... Requires a good bit of up front work, but it saves us a ton of pain at the end The following examples assume you’ve already got database tables Also, a note: because Hibernate can operate on multiple table types, it has its own query language variant called HQL ...
... Requires a good bit of up front work, but it saves us a ton of pain at the end The following examples assume you’ve already got database tables Also, a note: because Hibernate can operate on multiple table types, it has its own query language variant called HQL ...
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.