ER Model
... deciding what are the candidate keys • Need to consider semantics of relationship set in selecting the primary key in case of more than one candidate key ...
... deciding what are the candidate keys • Need to consider semantics of relationship set in selecting the primary key in case of more than one candidate key ...
Database Tuning Principles, Experiments and Troubleshooting
... SCSI Controller Cache 2 Disks - Cache Size 80Mb ...
... SCSI Controller Cache 2 Disks - Cache Size 80Mb ...
Physical Database Design
... tuple (row) in a relation. For example, a query of an employee relation might ask the question “ what is the salary of Mr. Smith?” . This query will return the row containing details about Mr. Smith. ...
... tuple (row) in a relation. For example, a query of an employee relation might ask the question “ what is the salary of Mr. Smith?” . This query will return the row containing details about Mr. Smith. ...
Module 1: Introduction
... SQL Call Level Interface (CLI) standard similar to ODBC interface, but ...
... SQL Call Level Interface (CLI) standard similar to ODBC interface, but ...
ppt - Avi Silberschatz
... The subset of R2 is a foreign key referencing K1 in relation r1, if for every t2 in r2 there must be a tuple t1 in r1 such that t1[K1] = t2[]. Referential integrity constraint also called subset dependency since its ...
... The subset of R2 is a foreign key referencing K1 in relation r1, if for every t2 in r2 there must be a tuple t1 in r1 such that t1[K1] = t2[]. Referential integrity constraint also called subset dependency since its ...
The Relational Data Model - Computer Science, Stony Brook
... 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 relation) If no row exists in R2 => violation of referential integrity ...
... 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 relation) If no row exists in R2 => violation of referential integrity ...
Lecture X - Integrity Constrains
... The subset of R2 is a foreign key referencing K1 in relation r1, if for every t2 in r2 there must be a tuple t1 in r1 such that t1[K1] = t2[]. Referential integrity constraint also called subset dependency since its ...
... The subset of R2 is a foreign key referencing K1 in relation r1, if for every t2 in r2 there must be a tuple t1 in r1 such that t1[K1] = t2[]. Referential integrity constraint also called subset dependency since its ...
Referential Integrity
... Forms of authorization to modify the database schema: ! Index authorization - allows creation and deletion of indices. ! Resources authorization - allows creation of new relations. ! Alteration authorization - allows addition or deletion of attributes in ...
... Forms of authorization to modify the database schema: ! Index authorization - allows creation and deletion of indices. ! Resources authorization - allows creation of new relations. ! Alteration authorization - allows addition or deletion of attributes in ...
Module 1: Introduction
... The subset of R2 is a foreign key referencing K1 in relation r1, if for every t2 in r2 there must be a tuple t1 in r1 such that t1[K1] = t2[]. Referential integrity constraint also called subset dependency since its ...
... The subset of R2 is a foreign key referencing K1 in relation r1, if for every t2 in r2 there must be a tuple t1 in r1 such that t1[K1] = t2[]. Referential integrity constraint also called subset dependency since its ...
principles of effective database design
... 1) Make a list of the questions that you think Maine Widget will need answers for in order to straighten out their problem: they need to know which customers are buying what products. 2) Design a report for customer information, product information, and sales by customer on a word processor of your ...
... 1) Make a list of the questions that you think Maine Widget will need answers for in order to straighten out their problem: they need to know which customers are buying what products. 2) Design a report for customer information, product information, and sales by customer on a word processor of your ...
PowerPoint 10
... referential constraint between two tables. The columns in the referenced table must be a primary key or unique key. The values in one row of the referencing columns must occur in a single row in the referenced table. Most of the time, a foreign key reflects a one to many relationship. ...
... referential constraint between two tables. The columns in the referenced table must be a primary key or unique key. The values in one row of the referencing columns must occur in a single row in the referenced table. Most of the time, a foreign key reflects a one to many relationship. ...
MS SQL SERVER 2005 / 2008 – Management Studio
... Note the llist of new tables created. Also note the options available when you right click on any of the table names. The Modify and Open Table work similar to MS Access. ...
... Note the llist of new tables created. Also note the options available when you right click on any of the table names. The Modify and Open Table work similar to MS Access. ...
Chapter 6: Integrity and Security Domain Constraints
... If this set is not empty, either the delete command is rejected as an error, or the tuples that reference t1 must themselves be deleted (cascading deletions are possible). ...
... If this set is not empty, either the delete command is rejected as an error, or the tuples that reference t1 must themselves be deleted (cascading deletions are possible). ...
Slides01
... • Works in CS180, because each Lab Aid works for all students. Connection studentLabAid is only via the course. • But what if students were divided into sections, each headed by a LabAid? ...
... • Works in CS180, because each Lab Aid works for all students. Connection studentLabAid is only via the course. • But what if students were divided into sections, each headed by a LabAid? ...
Document
... SQL > ALTER TABLE MODIFY (
... SQL > ALTER TABLE
