Chapter 5 - The Relational Data Model and Relational Database Constraints present contents as: Relational model concepts, relational model constraints and relational database schemas, update operations and dealing with constraint violations.
The relational Model of Data is based on the concept of a Relation.
A Relation is a mathematical concept based on the ideas of sets.
The strength of the relational approach to data management comes from the formal foundation provided by the theory of relations.
We review the essentials of the relational approach in this chapter.
A constraint is proposed in the Centering approach to pronoun resolution in discourse. This "property-sharing" constraint requires that two pronominal expressions that retain the same Cb across adjacent utterances share a certain common grammatical property. This property is expressed along the dimension of the grammatical function SUBJECT for both Japanese and English discourses, where different pronominal forms are primarily used to realize the Cb. It is the zero pronominal in Japanese, and the (unstressed) overt pronoun in English.
Database System: Chapter 2 - The Relational Data Model & SQL includes about Relational Model Concepts, Relational Model Constraints and Relational Database Schemas, Update Operations and Dealing with Constraint Violations, Basic SQL.
Databases and database systems are an essential
component of life in modern society: most of us
encounter several activities every day that involve some interaction with a database.
For example, if we go to the bank to deposit or withdraw funds, if we make a hotel
or airline reservation, if we access a computerized library catalog to search for a bibliographic
item, or if we purchase something online—such as a book, toy, or computer—
chances are that our activities will involve someone or some computer
program accessing a database.
As you will see, the maths shows that the trick will always work if
the spectator does what’s expected of them and follows the rules.
Mathematically we call the things the spectator must do, like choose
different digits and put them in the right order, the constraints. In this trick
it’s the presentation (where we say ‘lets make it harder’ and so on) that
makes sure these constraints are followed. If we let things go astray and,
for example, let the spectator choose digits that were the same we would
have a constraint violation and it would upset the maths....
This paper discusses the application of a previously reported theory of explanation rhetoric (Maybury, 1988b) to the task of explaining constraint violations in a hybrid rule/frame based system for resource allocation (Dawson et al, 1987). This research illustrates how discourse strategies of explanation, textual connectives, and additional justification knowledge can be applied to enhance the cohesiveness, structure, and clarity of knowledge based system explanations.
In this paper we present TroFi (Trope Finder), a system for automatically classifying literal and nonliteral usages of verbs through nearly unsupervised word-sense disambiguation and clustering techniques. TroFi uses sentential context instead of selectional constraint violations or paths in semantic hierarchies. It also uses literal and nonliteral seed sets acquired and cleaned without human supervision in order to bootstrap learning.
Principles of Database Management Systems - Notes 6: Crash Recovery presents about Integrity or correctness of data, Integrity or consistency constraints, prevent/fix violations, Failure Model, Context of failure model.
Nếu bạn cố thử chạy phát biểu INSERT này, bạn sẽ nhận một thông báo lỗi từ co8 sở dữ liệu : Violation of PRIMARY KEY constraint 'PK_Customers'. Cannot insert duplicate key in object 'Customers'. The statement has been terminated. Hãy xem nhũng gì sẽ sảy ra khi bạn cố sửa đổi một khoá chính ở bảng cha có một giá trị đã được tham chiếu từ một khoá phụ trong bảng con.
Syntactic analysis inﬂuences the way in which the source sentence is translated. Previous efforts add syntactic constraints to phrase-based translation by directly rewarding/punishing a hypothesis whenever it matches/violates source-side constituents. We present a new model that automatically learns syntactic constraints, including but not limited to constituent matching/violation, from training corpus. The model brackets a source phrase as to whether it satisﬁes the learnt syntactic constraints. The bracketed phrases are then translated as a whole unit by the decoder. ...
Sensor networks and pervasive computing systems intimately
combine computation, communication and interactions with the physical
world, thus increasing the complexity of the development effort, violating
communication protocol layering, and making traditional network
diagnostics and debugging less effective at catching problems. Tighter
coupling between communication, computation, and interaction with the
physical world is likely to be an increasing trend in emerging edge networks
and pervasive systems.
Now on the same side a• the subjects' point of view.
We see the point of view indicated by •patlal delxls In the r e p o r t of problem solving as reflec~ir~ an underlying allocation of effort (or attention). Pew errors occur with problem elements that •re given processing effort, while constraints that •re given little attention are more often violated. %n this way, these reports are reflecting changes Zn the organization of the problem element• that occur over the course of reaching a solution. ...
Oatlal delxls In the r e p o r t of problem solving as reflec~ir~ an underlying allocation of effort (or attention). Pew errors occur with problem elements that •re given processing effort, while constraints that •re given little attention are more often violated. %n this way, these reports are reflecting changes Zn the organization of the problem element• that occur over the course of reaching a solution.