Applied Mathematics for Database Professionals phần 7 pot

... of a database; they enable you to extract infor- mation from a database that is relevant for you. • You can formally represent a query as a function over a database universe. For every database ... encounter? CHAPTER 10 ■ DATA MANIPULATION 2 37 7451CH10.qxd 5 /7/ 07 11:36 AM Page 2 37 Let’s start with a simple example using the database design that was introduced in C hapter...

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... http://en.wikipedia.org/wiki/ Orthogonality. xxv 74 51FM.qxd 5/ 17/ 07 10:41 AM Page xxv Applied Mathematics for Database Professionals Copyright © 20 07 by Lex de Haan and Toon Koppelaars All rights ... . . . 3 67 v 74 51FM.qxd 5/ 17/ 07 10:41 AM Page v The Mathematics Everything should be made as simple as possible, but not simpler. Albert Einstein (1 879 –1955) PART 1 74...

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... and therefore a source of confusion. The section “Normal Forms” discusses normal forms in logic—not to be confused with normal forms of data (defined for database design purposes). Normal forms ... following two normal forms for predicates: • Conjunctive normal form is a predicate rewritten in the format of an iterated AND. • Disjunctive normal form is a predicate rewritten in the forma...

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... AND FUNCTIONS 79 74 51CH04.qxd 5/4/ 07 2:43 PM Page 79 74 51CH04.qxd 5/4/ 07 2:43 PM Page 88 In this formula, D 1 , D 2 , , D n are known as the disjunction members—or just disjuncts for short. Each ... formal definition of a database state. We’ll often use a shorthand name for a given database state for convenience of reference in the text. Database Database is an informal...

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... such tables. Defin- ition 5-4 for mally defines this operator. CHAPTER 5 ■ TABLES AND DATABASE STATES 1 07 7451CH05.qxd 5/4/ 07 3: 57 PM Page 1 07 7451CH05.qxd 5/4/ 07 3: 57 PM Page 116 Shorthand Notation Writing ... T able 3-2 for this. ■Note The empty set is often used as the initial sta te for a given table structure. CHAPTER 5 ■ TABLES AND DATABASE STATES 95 74 51CH05.qx...

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... total of 26 (possible) database states. You might want to verify this for yourself. CHAPTER 7 ■ SPECIFYING DATABASE DESIGNS 170 74 51CH 07. qxd 5/15/ 07 9:43 AM Page 170 Listing 7- 26. Table Universe ... follo w , y ou ’ ll find the formal specification for each of these named constraints. CHAPTER 7 ■ SPECIFYING DATABASE DESIGNS 171 74 51CH 07. qxd 5/15/ 07 9:43 AM Page 17...

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... DATABASE DESIGNS 177 74 51CH 07. qxd 5/15/ 07 9:43 AM Page 177 Completing the Example Database Design Let’s now demonstrate all this by specifying state transition constraints for the example data- base ... rid of PTIJ13. Do y ou see ho w to change PTIJ15? CHAPTER 7 ■ SPECIFYING DATABASE DESIGNS184 74 51CH 07. qxd 5/15/ 07 9:43 AM Page 184 74 51CH08.qxd 5 /7/ 07 11:22 AM Pag...

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... first manager in department 20, therefore . . . , and so on. CHAPTER 11 ■ IMPLEMENTING DATABASE DESIGNS IN ORACLE 271 74 51CH11.qxd 5/15/ 07 2:26 PM Page 271 The SQL standard allows you to specify ... pl_dummy from DUAL CHAPTER 11 ■ IMPLEMENTING DATABASE DESIGNS IN ORACLE 270 74 51CH11.qxd 5/15/ 07 2:26 PM Page 270 In the relational model of data, all attributes in a database desi...

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... ■ FORMAL DEFINITION OF EXAMPLE DATABASE3 14 74 51AppA.qxd 5/15/ 07 9:45 AM Page 314 Formal Definition of Example Database In this appendix, we deliver the formal specification of the example database ... tab_SREP ) APPENDIX A ■ FORMAL DEFINITION OF EXAMPLE DATABASE3 24 74 51AppA.qxd 5/15/ 07 9:45 AM Page 324 74 51AppA.qxd 5/15/ 07 9:45 AM Page 310 The following three listings (A-...

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... completeness, 16, 62, 262 functions, 67 87, 305 domain/range of, 71 into sets, 72 limitations of, 76 operations on, 75 77 over sets, 70 subsets of, 74 symbols for, 333 G generalization predicates, ... EXERCISES352 74 51AppE.qxd 5/15/ 07 1:43 PM Page 352 database management system (DBMS), 93. See also SQL DBMS database predicates, 1 17 136, 306 patterns of, 1 27 136 sample...

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