Applied Mathematics for Database Professionals phần 9 pdf

... Report RJ 599 , 196 9. Codd, E. F. The Relational Model For Database Management,Version 2. Reading, MA: Addison- Wesley, 199 0. Recommended Reading on Relational Database Management Date, C. J. Database ... ■ FORMAL DEFINITION OF EXAMPLE DATABASE3 14 7451AppA.qxd 5/15/07 9: 45 AM Page 314 Formal Definition of Example Database In this appendix, we deliver the formal specification...

Ngày tải lên: 08/08/2014, 18:21

... http://www.springeronline.com. For information on translations, please contact Apress directly at 2855 Telegraph Avenue, Suite 600, Berkeley, CA 94 705. Phone 510-5 49- 593 0, fax 510-5 49- 593 9, e-mail info@apress.com, ... Russell and Alfred North Whitehead (1861– 194 7), David Hilbert (1862– 194 3), John von Neumann ( 190 3– 195 7), Kurt Gödel ( 190 6– 197 8), and Alfred Tarski ( 190 2...

Ngày tải lên: 08/08/2014, 18:21

... 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...

Ngày tải lên: 08/08/2014, 18:21

... shorthand name for a given database universe (just symbols) for conven- ience of reference in the text. Database State Database state is a formal term. It is a mathematical construct used to formally ... text. Database Database is an informal term for the actual (business) data that is stored in a computer in a structured way (that is, conforming to the database design). Abstr...

Ngày tải lên: 08/08/2014, 18:21

... (partno; [1 99 9]) ,(name; varchar(12)) ,(instock; [0 99 ]) ,(price; [1 500]) } CHAPTER 5 ■ TABLES AND DATABASE STATES 97 7451CH05.qxd 5/4/07 3:57 PM Page 97 Given table T11 and T6, you can formally ... chr_EMP chr_EMP := { (empno; [100 99 9]) ,(ename; varchar(20)) ,(job; {'MANAGER','CLERK','TRAINER'} ) ,(sal; [2000 90 00]) ,(deptno; [10 99 ]) } For...

Ngày tải lên: 08/08/2014, 18:21

... expression denotes set [1000 99 99] . The definition of characterization chr_EMP tells us the following: • EMPNO values are positive integers within the range 1000 to 99 99. • ENAME v alues ar e v ar iable ... limit regarding database professionals, then there cannot be a result with an average score of A for database professionals (r egardless of the course), and if ther e is a...

Ngày tải lên: 08/08/2014, 18:21

... 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 defining a database ... result by specifying database predicates. These database predicates are called database constraints. • This formal model is your—the database professional’s—reference of th...

Ngày tải lên: 08/08/2014, 18:21

... 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 ... database: tcrs1 := { (CODE;'AM4DP') , (DESC;&apos ;Applied Mathematics for Database Professionals& apos;) , (CAT;'DSG') , (DUR;5) } For your convenience,...

Ngày tải lên: 08/08/2014, 18:21

... Attribute Constraints for SREP Table Structure alter table SREP add constraint srp_chk_empno check (empno > 99 9); alter table SREP add constraint srp_chk_targ check (target > 99 99) ; alter table ... Attribute Constraints for MEMP Table Structure alter table MEMP add constraint mmp_chk_empno check (empno > 99 9); alter table MEMP add constraint mmp_chk_mgr check (mgr >...

Ngày tải lên: 08/08/2014, 18:21

... 143 defined, 93 queries and, 199 –201 specifying formally, 98 top-down view of, 141 transactions and, 221–233 database universe, 36, 77, 1 39, 306 defined, 92 queries and, 199 –216 sample database design and, ... 1 09 average operator (AVG), 112 binary relations, 69 cardinality of sets, 29 Cartesian product, 39 compatible functions, 77 database, 93 database design, 92 data...

Ngày tải lên: 08/08/2014, 18:21