Applied Mathematics for Database Professionals phần 3 docx

... all elements in P: 2>12 ∨ 3& gt;12 ∨ 5>12 ∨ 7>12 ∨ 11>12 ∨ 13& gt;12 Iterate y over all elements in P: 2> ;3 ∧ 3& gt ;3 ∧ 5> ;3 ∧ 7> ;3 ∧ 11> ;3 ∧ 13& gt ;3 You could now manually compute ... Normal Form (DNF) P-DNF := (SP 11 ∧ SP 12 ∧ SP 13 ∧ ∧ SP 1a ) ∨ (SP 2 1 ∧ SP 2 2 ∧ SP 2 3 ∧ ∧ SP 2 b ) ∨ (SP 31 ∧ SP 32 ∧ SP 33 ∧ ∧ SP 3c ) ∨ ∨ (SP n 1 ∧ SP n 2 ∧...

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... you to a formal way of specifying a database via a database state. Formal Representation of a Database State Let’s consider a simple database design involving two table structures: one for employees ... yearly bonus for man- agers; it is also a specialization of EMP1. Figure 6-8. Table MAN1 CHAPTER 6 ■ TUPLE, TABLE, AND DATABASE PREDICATES 133 7451CH06.qxd 5/14/07 10 :37 AM Pa...

Ngày tải lên: 08/08/2014, 18:21

... constraints, and formally specifies these for the given example database design. Chapter 9 shows how you can precisely formulate queries in mathematics , and Chapter 10 shows ho w you can formally specify ... Page xxv Applied Mathematics for Database Professionals Copyright © 2007 by Lex de Haan and Toon Koppelaars All rights reserved. No part of this work may be reproduced or...

Ngày tải lên: 08/08/2014, 18:21

... given: A := {1,2 ,3} B := {3, 4} Then A×B = { (1 ;3) , (1;4) , (2 ;3) , (2;4) , (3; 3), (3; 4) } CHAPTER 2 ■ SET THEORY: INTRODUCTION 39 7451CH02.qxd 5/4/07 2:12 PM Page 39 See Listing 2-6 for some examples ... check out for yourself t hat they are all T RUE . L isting 2-6. E xamples of Subset Propositions That Are True {1,2} ⊆ {1,2 ,3} {1,2} ⊂ {1,2 ,3} {1,2 ,3} ⊄ {1,2 ,3} {1,2...

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... limit regarding non -database professionals, then there cannot be a result with an average score of F for non -database professionals. This database pr edicate discards possible database states that ... SPECIFYING DATABASE DESIGNS166 7451CH07.qxd 5/15/07 9: 43 AM Page 166 ( ∀g1∈G: ( ∃g2∈G: g2(LLIMIT) < g1(LLIMIT) ) ⇒ #{ g3 | g3∈G ∧ g3(LLIMIT) < g1(LLIMIT) ∧ g3(ULIMIT) ≥...

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... 2 03 7451CH09.qxd 5/7/07 11:28 AM Page 2 03 ( ∑t∈{ o3∪c3| d3∈DEPT ∧ e3∈EMP ∧ o3∈OFFR ∧ c3∈CRS ∧ e3(EMPNO) = e1 ∧ e3(EMPNO) = o3(TRAINER) ∧ e3(DEPTNO) = d3(DEPTNO) ∧ o3(COURSE) = c3(CODE) ∧ o3(STATUS) ... set of database states called the database universe. It holds the admissible database states for the database being specified. You can con- struct a database universe by first d...

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... 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 ... be inserted into the database: tcrs1 := { (CODE;'AM4DP') , (DESC;&apos ;Applied Mathematics for Database Professionals& apos;) , (CAT;'DSG') , (DUR;5) } Fo...

Ngày tải lên: 08/08/2014, 18:21

... exists(select e3.* from EMP e3 where e3.DEPTNO = r.DEPTNO and e3.JOB = 'ADMIN')); exception when no_data_found then raise_application_error(-20999, 'Constraint EMP_TAB 03 is violated for ... update trigger in Oracle (see Listing 11 -31 ). Listing 11 -31 . EM3’s More Efficient Update Trigger for Constraint EMP_TAB 03 create trigger EMP_AUS_TAB 03 after update of DEPTN...

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... ■ FORMAL DEFINITION OF EXAMPLE DATABASE3 14 7451AppA.qxd 5/15/07 9:45 AM Page 31 4 Formal Definition of Example Database In this appendix, we deliver the formal specification of the example database ... g1(LLIMIT) ) ⇒ #{ g3 | g3∈G ∧ g3(LLIMIT) < g1(LLIMIT) ∧ g3(ULIMIT) ≥ g1(LLIMIT) ∧ g3(ULIMIT) < g1(ULIMIT) } = 1 ) } APPENDIX A ■ FORMAL DEFINITION OF EXAMPLE DATABASE3 20 7451AppA...

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... product, 39 compatible functions, 77 database, 93 database design, 92 database management system (DBMS), 93 database state, 93 database universe, 92 database variable, 92 disjoint sets, 34 function ... 262–265 sample database universe specification and, 33 9 specifying, 1 53, 1 63 tuple-in-join predicates, 135 , 2 93, 30 6 tuple predicates, 117–122, 30 6 over sets, 119...

Ngày tải lên: 08/08/2014, 18:21