Implementing a Categorical Information System
... instance of their source type they return an instance of their target type. The other three components of an EA sketch do not appear in ER diagrams and they express database constraints. In EASIK they are indicated graphically. The second component is a set of commutative diagrams. A commutative dia ...
... instance of their source type they return an instance of their target type. The other three components of an EA sketch do not appear in ER diagrams and they express database constraints. In EASIK they are indicated graphically. The second component is a set of commutative diagrams. A commutative dia ...
Sudarshan - CSE, IIT Bombay
... In alpha versions at best Some relational database provide support for storing XML data, but no support or poor support for quering complex XML data XML query language is still being standardized (XQuery) Initial XML query implementations likely to be poor compared to relational query implem ...
... In alpha versions at best Some relational database provide support for storing XML data, but no support or poor support for quering complex XML data XML query language is still being standardized (XQuery) Initial XML query implementations likely to be poor compared to relational query implem ...
Relationship Sets
... Relationship sets may involve more than two entity sets. E.g. Suppose employees of a bank may have jobs (responsibilities) at multiple branches, with different jobs at different branches. Then there is a ternary relationship set between entity sets employee, job and branch ...
... Relationship sets may involve more than two entity sets. E.g. Suppose employees of a bank may have jobs (responsibilities) at multiple branches, with different jobs at different branches. Then there is a ternary relationship set between entity sets employee, job and branch ...
The Entity-Relationship Model
... Relationship: Association among two or more entities. E.g., Attishoo works in Pharmacy department Relationship Set: Collection of similar relationships ...
... Relationship: Association among two or more entities. E.g., Attishoo works in Pharmacy department Relationship Set: Collection of similar relationships ...
Hippo: a System for Computing Consistent Answers to a
... Integrity constraints express important properties of data, but the task of preserving data consistency is becoming increasingly problematic with new database applications. For example, in the case of integration of several data sources, even if the sources are separately consistent, the integrated ...
... Integrity constraints express important properties of data, but the task of preserving data consistency is becoming increasingly problematic with new database applications. For example, in the case of integration of several data sources, even if the sources are separately consistent, the integrated ...
Having PHP get data from a MySQL database
... • PHP must connect to the database, perform a SQL select statement of the appropriate table or tables and then parse the query result and display the ...
... • PHP must connect to the database, perform a SQL select statement of the appropriate table or tables and then parse the query result and display the ...
Models of Databases and Database Design
... Full functional dependence applies to tables with composite keys. Column Y in relational table R is fully functional on X of R if it is functionally dependent on X and not functionally dependent upon any subset of X. Full functional dependence means that when a primary key is composite, made of two ...
... Full functional dependence applies to tables with composite keys. Column Y in relational table R is fully functional on X of R if it is functionally dependent on X and not functionally dependent upon any subset of X. Full functional dependence means that when a primary key is composite, made of two ...
PPT - ETH Systems Group
... Create several connections to the database Grab an unused connection before accessing DB Execute statement using that connection Why? Do not block the database with heavy queries Rule of thumb: 5 – 10 connections (too many connections will hurt performance and avail.) ...
... Create several connections to the database Grab an unused connection before accessing DB Execute statement using that connection Why? Do not block the database with heavy queries Rule of thumb: 5 – 10 connections (too many connections will hurt performance and avail.) ...
aliyazici.atilim.edu.tr
... 4NF: A table is in 4NF if and only if , for every one of its non-trivial multivalued dependencies X →→ Y, X is a superkey—that is, X is either a candidate key or a superset thereof. 5NF: A table is said to be in the 5NF if and only if every join dependency in it is implied by the candidate keys. • A ...
... 4NF: A table is in 4NF if and only if , for every one of its non-trivial multivalued dependencies X →→ Y, X is a superkey—that is, X is either a candidate key or a superset thereof. 5NF: A table is said to be in the 5NF if and only if every join dependency in it is implied by the candidate keys. • A ...
Chapter15 - Columbia College
... • Creating a new copy each time is essential – If it were to be created once and then stored on the user’s computer, then there would be two copies of the information ...
... • Creating a new copy each time is essential – If it were to be created once and then stored on the user’s computer, then there would be two copies of the information ...
E3_alumni_database
... properties are apartment, house, or townhouse. Tenants rent these properties through a lease and make a monthly payment for it when they occupy it. The properties need services (cutting lawn, painting, plumbing, etc.) which are provided by Service providers. Please read the instruction given above f ...
... properties are apartment, house, or townhouse. Tenants rent these properties through a lease and make a monthly payment for it when they occupy it. The properties need services (cutting lawn, painting, plumbing, etc.) which are provided by Service providers. Please read the instruction given above f ...
Slides1
... Basic structure of DBMS Queries the database Create/Update table content/structure Design the database (ER model) Web interface for database A project that covers all contents in the course and you can implement a DBMS from scratch ...
... Basic structure of DBMS Queries the database Create/Update table content/structure Design the database (ER model) Web interface for database A project that covers all contents in the course and you can implement a DBMS from scratch ...
Document
... condition that compares specified columns of each table – Outcome does not eliminate duplicate columns – Condition or criterion to join tables must be explicitly defined – Takes its name from the equality comparison operator (=) used in the condition ...
... condition that compares specified columns of each table – Outcome does not eliminate duplicate columns – Condition or criterion to join tables must be explicitly defined – Takes its name from the equality comparison operator (=) used in the condition ...
DB2 Overview
... Compiled procedures can be invoked by any user application Provides consistent functionality (don’t need to rewrite SQL ‘inserts’, can just call a stored procedure) ...
... Compiled procedures can be invoked by any user application Provides consistent functionality (don’t need to rewrite SQL ‘inserts’, can just call a stored procedure) ...
Database-Systems-Design-Implementation-and-Management
... Notice that in equijoins, the common attribute appears from both tables. It is normal to prefix the attribute name with the table name when an attribute appears more than once in a table. This maintains the requirement that attribute names be unique within a relational table. ...
... Notice that in equijoins, the common attribute appears from both tables. It is normal to prefix the attribute name with the table name when an attribute appears more than once in a table. This maintains the requirement that attribute names be unique within a relational table. ...
D O M A I N S P... Proceedings of DSL'99: The 2 Conference on Domain-Specific Languages
... Another typical operation on relations is join ./ that combines two relations by merging tuples whose common attributes have identical values. Hence, if we join the P residents table Name President Starr False Clinton True with ...
... Another typical operation on relations is join ./ that combines two relations by merging tuples whose common attributes have identical values. Hence, if we join the P residents table Name President Starr False Clinton True with ...
ppt
... This form is essential if the key consists of more than one attribute. May be used even for one-attribute keys. ...
... This form is essential if the key consists of more than one attribute. May be used even for one-attribute keys. ...
Integration of databases and World Wide Web based on Open
... are domains of that attributes. We define D=D1∪...∪Dn. Then we can define row or record as function t:R →D, with property that t((Ai,Di))∈Di. Intuitively said, records are n-tuples of values, where ith value is chosen from domain of ith attribute. In cases when attribute domains are known form seman ...
... are domains of that attributes. We define D=D1∪...∪Dn. Then we can define row or record as function t:R →D, with property that t((Ai,Di))∈Di. Intuitively said, records are n-tuples of values, where ith value is chosen from domain of ith attribute. In cases when attribute domains are known form seman ...
NoSQL Databases
... Over the last years, distributed web applications have become more and more popular. Especially widely used services like Facebook, Google or Amazon have to store and process large amounts of data. Obviously such data can not be handled by single-node systems, thus distributed storage solutions are ...
... Over the last years, distributed web applications have become more and more popular. Especially widely used services like Facebook, Google or Amazon have to store and process large amounts of data. Obviously such data can not be handled by single-node systems, thus distributed storage solutions are ...
SQL: Queries, Programming, Triggers
... Redundancies in a relational table lead to anomalies such as update and deletion anomalies. A relation is in Boyce-Codd normal form (BCNF), if the left sides of all non-trivial FDs contain a key. A schema in BCNF avoids the above anomalies. A given schema can be decomposed into subsets of at ...
... Redundancies in a relational table lead to anomalies such as update and deletion anomalies. A relation is in Boyce-Codd normal form (BCNF), if the left sides of all non-trivial FDs contain a key. A schema in BCNF avoids the above anomalies. A given schema can be decomposed into subsets of at ...