Microsoft SQL Server Note
... The value of a specific column may or may not be required. In the Customers table, the CustomerID column does not allow NUUL values. During an insert, this column must have a value if you want the insert to be successful. During a column as NOT NULL means that a value is required. On the other hand, ...
... The value of a specific column may or may not be required. In the Customers table, the CustomerID column does not allow NUUL values. During an insert, this column must have a value if you want the insert to be successful. During a column as NOT NULL means that a value is required. On the other hand, ...
Connecting Business Objects to Relational Databases
... relational database rather than an object-oriented database. Whatever the reason, a system that stores objects in a relational database needs to provide a design that reduces the impedance mismatch. This paper describes only a part of a pattern language for mapping objects to relations, but it descr ...
... relational database rather than an object-oriented database. Whatever the reason, a system that stores objects in a relational database needs to provide a design that reduces the impedance mismatch. This paper describes only a part of a pattern language for mapping objects to relations, but it descr ...
DBMS Lab
... Department table. But, in the Employee table all the employee records are from the first four departments only. Now a join operation on these two tables would retrieve only those rows where the department numbers are matching, i.e. either of those departments where some employee has been recruited. ...
... Department table. But, in the Employee table all the employee records are from the first four departments only. Now a join operation on these two tables would retrieve only those rows where the department numbers are matching, i.e. either of those departments where some employee has been recruited. ...
24Sp157L3ERmodel1
... Use of entity sets vs. relationship sets Possible guideline is to designate a relationship set to describe an action that occurs between entities Binary versus n-ary relationship sets Although it is possible to replace any nonbinary (n-ary, for n > 2) relationship set by a number of distinct bin ...
... Use of entity sets vs. relationship sets Possible guideline is to designate a relationship set to describe an action that occurs between entities Binary versus n-ary relationship sets Although it is possible to replace any nonbinary (n-ary, for n > 2) relationship set by a number of distinct bin ...
One-Copy Serializability with Snapshot Isolation under
... With careful design and engineering, SI engines can be replicated to get even higher performance with a replicated form of SI such as Generalized Snapshot Isolation (GSI) [13], which is also not serializable. The objective of this paper is to provide a concurrency control algorithm for replicated SI ...
... With careful design and engineering, SI engines can be replicated to get even higher performance with a replicated form of SI such as Generalized Snapshot Isolation (GSI) [13], which is also not serializable. The objective of this paper is to provide a concurrency control algorithm for replicated SI ...
Ch.8 - Faculty Website Listing
... then dept_name would be a candidate key.” This example also shows how functional dependencies (FD) are different from keys: a FD captures a rule that is in general more granular than a key. A key is a FD, but a FD is not always a key! ...
... then dept_name would be a candidate key.” This example also shows how functional dependencies (FD) are different from keys: a FD captures a rule that is in general more granular than a key. A key is a FD, but a FD is not always a key! ...
UNIX Tutorial One - Computer Science Departmrnt
... Write a program to check whether the given number is Armstrong or not Write a program to generate all prime numbers below 100. Write a program to demonstrate the GOTO statement. Write a program to demonstrate %type and %rowtype ...
... Write a program to check whether the given number is Armstrong or not Write a program to generate all prime numbers below 100. Write a program to demonstrate the GOTO statement. Write a program to demonstrate %type and %rowtype ...
File - ashwani goyal
... 3.5.5 Translating Weak Entity Sets 73 3.5.6 Translating Class Hierarchies 74 3.5.7 Translating ER Diagrams with Aggregation 75 3.5.8 ER to Relational: Additional Examples * 76 3.6 Introduction to Views 78 3.6.1 Views, Data Independence, Security 79 3.6.2 Updates on Views 79 3.7 Destroying/Altering T ...
... 3.5.5 Translating Weak Entity Sets 73 3.5.6 Translating Class Hierarchies 74 3.5.7 Translating ER Diagrams with Aggregation 75 3.5.8 ER to Relational: Additional Examples * 76 3.6 Introduction to Views 78 3.6.1 Views, Data Independence, Security 79 3.6.2 Updates on Views 79 3.7 Destroying/Altering T ...
InterBase XE Quick Start
... Throughout this Quick Start, you are instructed to enter SQL statements manually at the beginning of each new topic in order to give you a hands-on experience. Then you are instructed to read in one of the SQL scripts that accompany this document. These steps allows you to create a database that is ...
... Throughout this Quick Start, you are instructed to enter SQL statements manually at the beginning of each new topic in order to give you a hands-on experience. Then you are instructed to read in one of the SQL scripts that accompany this document. These steps allows you to create a database that is ...
The Volcano Optimizer Generator: Extensibility and Efficient
... expression whose result should be sorted on the join attribute, hybrid hash join does not qualify while merge-join qualifies with the requirement that its inputs be sorted. The sort enforcer also passes the test, and the requirements for its input do not include sort order. When the input to the sor ...
... expression whose result should be sorted on the join attribute, hybrid hash join does not qualify while merge-join qualifies with the requirement that its inputs be sorted. The sort enforcer also passes the test, and the requirements for its input do not include sort order. When the input to the sor ...
Learning PHP and MySQL: by Knowledge flow
... These are nested queries. A query that is in another query and this is embedded within the where clause. Sub-Queries are usually used to return data which will be further used in the main query. Rules of Sub- queries It has to be enclosed within parenthesis. It can have only one column in SELECT cla ...
... These are nested queries. A query that is in another query and this is embedded within the where clause. Sub-Queries are usually used to return data which will be further used in the main query. Rules of Sub- queries It has to be enclosed within parenthesis. It can have only one column in SELECT cla ...
Chapter 7: Relational Database Design
... X is a proper subset of some key K. Such a dependency is sometimes called a partial dependency. In this case, we store (X,A) pairs redundantly. X is not a proper subset of any key. Such a dependency is sometimes called a transitive dependency, because it means we have a chain of dependencies K ...
... X is a proper subset of some key K. Such a dependency is sometimes called a partial dependency. In this case, we store (X,A) pairs redundantly. X is not a proper subset of any key. Such a dependency is sometimes called a transitive dependency, because it means we have a chain of dependencies K ...
Fault-Based Testing of Database Application Programs with
... IWKR: The identifying / weak entity type replacement operator determines whether an (expression on) identifying or weak entity type(s) is involved in the relation. For an identifying entity type, IWKR will substitute it with a weak entity type. For a weak entity type, IWKR will substitute it with an ...
... IWKR: The identifying / weak entity type replacement operator determines whether an (expression on) identifying or weak entity type(s) is involved in the relation. For an identifying entity type, IWKR will substitute it with a weak entity type. For a weak entity type, IWKR will substitute it with an ...
Relational Model Advanced Topics in Microsoft SQL Server
... Customer table in the examples shown above, there are indexes on the CustomerNum field, the CreditLimit and the RepNum. The index key for an index can be any field or combination of fields in any table. After creating an index, you can use it to facilitate data retrieval. In powerful mainframe relat ...
... Customer table in the examples shown above, there are indexes on the CustomerNum field, the CreditLimit and the RepNum. The index key for an index can be any field or combination of fields in any table. After creating an index, you can use it to facilitate data retrieval. In powerful mainframe relat ...
Succeeding in Business with Microsoft Excel 2003
... common field with at least one of the other tables or queries Otherwise Access displays every combination of records between two tables ...
... common field with at least one of the other tables or queries Otherwise Access displays every combination of records between two tables ...
PowerPoint
... e.g., - Cannot find tuples with given key quickly - Always have to read the full relation ...
... e.g., - Cannot find tuples with given key quickly - Always have to read the full relation ...
Document in
... attributes. To provide this the proposed system integrates content based and spatial query methods in order to enable searching for images by arrangements of regions. The objective of content based visual query (CBVQ) is to retrieve the images that are most similar to the user’s query image by perfo ...
... attributes. To provide this the proposed system integrates content based and spatial query methods in order to enable searching for images by arrangements of regions. The objective of content based visual query (CBVQ) is to retrieve the images that are most similar to the user’s query image by perfo ...
Expression and Enforcement of Dynamic Integrity Constraints
... necessary to centralize the specification of constraints. Consequently, the consistency constraints that hold in a particular application area have to be specified in the conceptual schema that describes the semantics of the application area. System software will then enforce these constraints auto ...
... necessary to centralize the specification of constraints. Consequently, the consistency constraints that hold in a particular application area have to be specified in the conceptual schema that describes the semantics of the application area. System software will then enforce these constraints auto ...
A Practical Theory of Language-Integrated Query
... difficult to use as one language. The host and query languages often use different notations for the same thing, and convenient abstractions such as higher-order functions and nesting may not be available in the query language. Interfacing between the two adds to the mental burden on the programmer ...
... difficult to use as one language. The host and query languages often use different notations for the same thing, and convenient abstractions such as higher-order functions and nesting may not be available in the query language. Interfacing between the two adds to the mental burden on the programmer ...
Integrating Spatial and Temporal Relationship
... requirements specifications. Second, in addition to reports on existing spatial databases [8]-[14] and temporal databases [15][19], many recent papers [18], [19]-[28] have reported spatiotemporal models and their operations, which explicitly record spatial changes over time as they relate to specifi ...
... requirements specifications. Second, in addition to reports on existing spatial databases [8]-[14] and temporal databases [15][19], many recent papers [18], [19]-[28] have reported spatiotemporal models and their operations, which explicitly record spatial changes over time as they relate to specifi ...