Applied Mathematics for Database Professionals phần 2 ppt

... 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, 3} ⊆ {1 ,2, 3} ∅⊆{1 ,2, 3} The ... for a set specification. T ake a look at the example in Listing 2- 4. CHAPTER 2 ■ SET THEORY: INTRODUCTION 27 7451CH 02. qxd 5/4/07 2: 12 PM Page 27 And B×A = { (...

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... e.EMPNO and o2.TRAINER = 120 6 and o2.STATUS = 'CONF' and to_char(o2.STARTS,'YYYY') = &apos ;20 03')) CHAPTER 9 ■ DATA RETRIEVAL2 12 7451CH09.qxd 5/7/07 11 :28 AM Page 21 2 FEd: ... 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 firs...

Ngày tải lên: 08/08/2014, 18:21

... Page xxv Applied Mathematics for Database Professionals Copyright © 20 07 by Lex de Haan and Toon Koppelaars All rights reserved. No part of this work may be reproduced or transmitted in any form ... 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...

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... Disjunctive 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 ∧ SP n 3 ∧ ∧ SP n d ) In ... (Z ;2) , (R;1) } b. { (X;1), (Y;3) } ∩ { (X;1), (Y ;2) , (X ;2) } c. { (X;1), (Y;3) } ∪ { (X;1), (X ;2) } d. { (X;1), (Y ;2) } ∩ { (X;1), (Y ;2) , (X ;2) }↓{Y} e. { p | p∈{X,Y}×...

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... AND DATABASE PREDICATES 122 7451CH06.qxd 5/14/07 10:37 AM Page 122 Listing 6 -2. Example Tuples t0 Through t6 t0 := { (empno;101), (begindate;'01-aug -20 05'), (enddate;'31-mar -20 07') ... (X;1), (Y ;2) , (Z;-1) }, { (X;1), (Y ;2) , (Z;0) }, { (X;1), (Y ;2) , (Z;1) } , { (X ;2) , (Y;0), (Z;-1) }, { (X ;2) , (Y;0), (Z;0) }, { (X ;2) , (Y;0), (Z;1) } , { (X ;2) , (Y;1),...

Ngày tải lên: 08/08/2014, 18:21

... tables ( T1, T2, and T3): ( ∀t1∈T1: ( ∀t2∈T2: ( ∀t3∈T3: (t1↓A=t2↓A ∧ t2↓B=t3↓B) ⇒ P(t1∪t2∪t3) ) ) ) In this pattern, A represents the set of join attributes for tables T1 and T2, and B represents the ... 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...

Ngày tải lên: 08/08/2014, 18:21

... ■ IMPLEMENTING DATABASE DESIGNS IN ORACLE2 42 7451CH11.qxd 5/15/07 2: 26 PM Page 24 2 Here are equivalent formal and SQL specifications for transaction ETX2: F Ea : dbs ↓{ EMP,SREP,MEMP,TERM,DEPT,GRD,CRS,OFFR,HIST} ∪ { ... 'PRESIDENT' then declare pl_num_presidents number; begin CHAPTER 11 ■ IMPLEMENTING DATABASE DESIGNS IN ORACLE2 52 7451CH11.qxd 5/15/07 2: 26 PM Page...

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... DUAL where not exists(select e2.* from EMP e2 CHAPTER 11 ■ IMPLEMENTING DATABASE DESIGNS IN ORACLE 28 3 7451CH11.qxd 5/15/07 2: 26 PM Page 28 3 Listing 11- 32. DI Code for DEPT_TAB01 in Case of Updates create ... department 20 , then this manager might be the first manager in department 20 , therefore . . . , and so on. CHAPTER 11 ■ IMPLEMENTING DATABASE DESIGNS IN ORACLE 27 1 745...

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... ∧ e(EMPNO) = r2(STUD) ∧ r2↓{COURSE,STARTS} = o2↓{COURSE,STARTS} ∧ o2(COURSE) = c2(COURSE) ) ⇒ ( o1↓{COURSE,STARTS} = o2↓{COURSE,STARTS} ∨ o1(STARTS) ≥ o2(STARTS) + c2(DUR) ∨ o2(STARTS) ≥ o1(STARTS) ... listings (A -26 , A -27 , and A -28 ) sho w the attr ibute-v alue sets, the tuple universe, and the table universe for REG, respectively. APPENDIX A ■ FORMAL DEFINITION OF EXAMPLE DATABASE...

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... databases, 141 transactions, 22 1 23 7, 28 4, 306 autonomous, 28 6 business logic code and, 24 4 concurrent, 26 6, 28 4, 29 8 data integrity code execution models for , 26 5 28 4 examples of, 22 6 23 6 formally ... command, 24 8, 29 2 always execution model, 26 8 application locks, 28 6 28 9 associativity, 11, 19, 48 attribute constraints, 1 42, 22 2, 22 4, 306 data integr it...

Ngày tải lên: 08/08/2014, 18:21