【正文】 the very first annual Achievement Award from the international DB2 Users Group: and another annual achievement award from DAMA in 2020. Computerworld, in celebration of the 25th anniversary of its publication, selected him as one of 25 individuals in or related to the field of puting who have had the most effect on our society. And Forbes magazine, which in December 2020 published a list of the most im。 elected member of the National Academy of Engineering。 elected ACM Fellow。Silberschatz, Korth and Sudarshan Database System Concepts Codd39。 and they laid the foundation for an entire new industry, the relational database industry, now worth many billions of dollars a year. In fact, not only did Codd39。s, he turned his attention to the problem of managing large mercial databases — and over the next few years he created, single handed, the invention with which his name will forever be associated: the relational model of data. An Appreciation by C. J. Date 169。Silberschatz, Korth and Sudarshan Database System Concepts Ted Codd was a genuine puting pioneer. He was also an inspiration to all of us who had the fortune to know him and work with him. He began his career in 1949 as a programming mathematician for IBM on the Selective Sequence Electronic Calculator. He subsequently participated in the development of several important IBM products, including its first mercial electronic puter (IBM 701) and the STRETCH machine, which led to IBM39。s life changed in 1983, when he suffered a serious injury from a fall. After his recovery, he retired from IBM and quit his beloved hobby of recreational flying. But he continued to work until 1999, muting to his San Jose office at Codd and Date Consulting Group, joined by longtime IBM collaborator Chris Date and mathematician Sharon Weinberg, another IBM colleague, who after 12 years of courtship became Codd39。 said son Ronald Codd, 47, of Alamo. ``He had this natural ability to see a situation and reach a conclusion that was a step beyond what people would ordinarily think 169。t think about what they added up to, but what they meant,39。 169。 Codd said, ``and I was disgusted.39。 he recalled in one interview. ``I began reading documentation,39。s Santa Teresa development laboratories in San Jose. There he found existing data management systems ``seatofthepants, with no theory at all,39。s model to build the first mercially available relational database management system. As plex and abstract as the math he loved, over the decades Codd retained his British accent, his dry wit and his love of a strong cup of tea, say family members. Codd was the youngest of seven children born to a leather processor and his schoolteacher wife in the remote town of Portland, England. He attended Oxford University on a full scholarship, earning degrees in math and chemistry. Although eligible for a military deferment because of his studies, he chose to fly in the Royal Air Force. 169。39。s landmark research paper in 1970, it was possible to store lots of information but analyzing it was difficult, requiring lines and lines of code for even simple tasks. 169。s online business data, died of heart failure at home Friday in Williams Island, Fla. He was 79. Bank accounts, credit cards, stock trading, travel reservations, online auctions and innumerable other nowroutine data transactions all rely on Codd39。39。S TRANSACTIONS By Lisa M. Krieger Mercury News 169。Silberschatz, Korth and Sudarshan Database System Concepts Chapter 4: Relational Model ? Structure of Relational Databases Posted on Sun, Apr. 20, 2020 IBM database developer dead at 79 `RELATIONAL39。Silberschatz, Korth and Sudarshan Database System Concepts Find the Entities, Attributes and Relationships Bi g H i t Vi deoR ent al R ecei ptA c c ou nt I d : 10 1 V ideo t ap e I d: 90 98 7 da t e: J an ua r y 9, 19 99 c os t : $2 . 99J an e B loc k10 10 M ain S t .A po pk a, FL 30 45 8E li z ab et h da t e du e: J an ua r y 11 , 19 99169。Silberschatz, Korth and Sudarshan Database System Concepts Relationship Types and Instances ? Marriage relationship type ? Person related to Person ? One person has the role of “wife” one has the role of “husband” ? Relationship type may have one or more attributes ? . weddingDate ? Marriage relationship (instance) ? Jane Block is married to Joe Block (relationship) ? Jane Block is the wife of Joe Block (role) ? Joe Block is the husband of Jane Block (role) ? Parentchild relationship type ? A person may have zero or more children 169。Silberschatz, Korth and Sudarshan Database System Concepts Relationships Between Entities ? Relationship type defines a set of associations among given types. ? Relationship Instances are particular relationships among objects. ? Examples of relationship types in pany database ? Manages: 1:1 between employee and department ? Worksfor: 1:N between department and employee ? Controls: 1:N between department and project 169。Silberschatz, Korth and Sudarshan Database System Concepts Entity Classes, Attributes and Constraints Cl a s s Att ri b u t e Co n s tra i n t s o r fu rth e rd e s c ri p t i o nCu s to m e r a c c o u n t Id k e yl a s tNa m e n o t n u l lfi rs tNa m ea d d re s so th e rUs e rsn u m b e rRe n t a l s d e ri v e dVi d e o t a p e v i d e o ta p e Id k e yti tl e n o t n u l lg e n rePa y Sta te m e n t d a te Pa i dh o u rs W o rk e da m o u n tPa i d169。Silberschatz, Korth and Sudarshan Database System Concepts Entity Classes for BigHit Video Entit y Cl ass Descr i pt i onCust om e r A c ust o m e r o f t he busine s sVi deot ape An it em i n t he r ent al i nv ent or yEm pl oy ee A per son w ho w or k s i n one o r m or est or esPay Stat em