һ
Щ˰ݿƣݿģʽ˼ݿϵͳ(OODBMS) ۻΪһ̸ʵǰݿûݿģʽ˼·ݿ˼·ûʹѧԶκһDBMSݿ⣬͡͡ϵ͡?ɣļϵͳҲѭ˼·
˼·ƹ淶ϵͳϵͳơƣҲݽṹơݿơOOSE¡ʼյع᳹˼·һһdzɵͳһ塣ݿֻ OOSE һڡ
ݿƵҪ
һݿƷ֣ͺʵ͡ʹӹݿӦõԳڹ鲢Լ(ʵ)ʱάԼĺϵʵȴѰҶݿӦʵ֣Ȼͨʵ塣һʵʵ1/10 ʱʹʵƷݿǴӶģͳģʵơ
һݿӦϵͳѭؿ裺1Ӧϵͳṹ2 ѡڽӦó DBMS ϵDBMSϵṹRDBMS3 ӦóʹõĻƽ̨ѡ˵DBMS(Oracle)Ϳ(PB)4 ݿ⣬дݿģʽSQL5 дȷȷ¼ݿûӿӦó6 ¼ݿݣ7 иݿصӦóȷϺݿݡ
ϸ裬мҪ˵
(1)ⲻٲģͣÿһз
ڹ·ϵͳУϸззвдһЩ¼ʱһЩƻġǵĵʽйأҲйء
(2)˳ǾԵģǴӵʼġ
(3)ԴݿӦϵͳ˵ҪѵIJӦϵͳƶݿơ
DBMSֺ֧ݿ
ܶݿӦϵͳ߲ݿƵԭǣ̫DBMSΪһǿ DBMSݿƾͲѡҪˡһЩݿ̲ijΪDBMSĿվݿûǶȣݿӦϵͳݿƷʹ߸㲻нܵݿ˼룬Ӧ DBMSݿƵ˼롣
ʵDBMSֻǸûΪѲõݿṩһ̨Ƿʹ̨ϵĵԼʲôϷȫȡûϷű͵()İš磬·ϵͳʹõݿϵͳԶάΪԪ֧йϵ֧ʵʵԵȫϵ RDBMSҪ̨ߡһĹϵݿ⡣
ġ ӦöģRDBMSģ͵ӳ
ݿ(ģʽ)Ƿ֧ӦϵͳĶģͣжǷݿϵͳĻ㡣ӦϵͳǰݿӦϵͳģݿģʽӳݿƵĹؼ
1.ݿģʽģ͵չ
һݿƶANSL/SPARCݿģʽ3ṹӽݿڲģʽ DBMS
ṩSQLģʽɸڲģʽۼɣݿû淶һЩļϡ磬·ּƻݿģʽݿģʽȣݿ⣬ͨID綨߽硣һĸģʽݿģʽı߽磬ʵݿ塢ضDBMSⲿӦóϢΡⲿģʽǴضûӦýǶȿݿģʽӲͬӦóͬһģʽԸֲͬⲿģʽ磺·̻ѯӦÿݿǹ·ϵľࡢֲʵȣ״ѯӦÿǹ·ϵȡ·εȣǿܷʵͬһIJͬӼ
ⲿӦϵͳԶģͽгʱӸӦóĶģͿӳ䵽ⲿģϣԴDz֮Ϊⲿģ͡ǣⲿģֻǸģ͵Ӽݿƺϵͳģ(֮Ϊģ)
ݿģ͵ӳ(μͼ1)
2.ģݿӳ
RDBMS ԶάΪԪģԶģɶάϵġ֮ģݿģ͵ӳݿı任̡йصı任£
1һӳΪһϵĿһԶĹϵʱһҲԶӦࡣ
ͼ1 ݿģʽģ͵չ
2ϵ(һһһԶࡢԶԼϵ)ӳжһӳΪһҲڶ䶨Ӧϵӳ䣬һӦ3ԡ
3һ̳еķϵԶԳࡢֱӳҲԲ常ӵиԣ֮ҲԲøӵȫԡ
4Զؼ̳еijֱӳԶζؼ̳еķϵҲӳһ
5ӳĿƵʹﵽĹϵʽ
3.ݿģʽҪӦϵͳ
ѡϵͳҲãݿҲãĿǷӦϵͳҪ
Թ·ּƻϵͳΪƻǴɶѵıЧشȡЩǼƻݿƵĹؼǵÿϽıͬģǿԴһſȥ洢ͬһֱ繫·±ֲһ⣬ûѯijµĹ?±ʱδӿȡ?ݿ˼Ӧһʶűڹ·ֵı±ϱʱϱλΪÿ¼ֶΣɻӴ࣬Ӳѯʱ䣬Чʡοÿű
λˡ˵ԣôأ˳ X3 ˮűX3 ˮűıṹ¡
1 X3ˮűıṹ
ǼӦöģӳݿģͺõͼ2ʾĽṹ
ÿһӦģӦһˮűͬһıͬһˮűˮűͳһˮűԸ־֡ύͽÿһűһˮţˮݿΨһģڿдκһűȷġ
ˮŵΪChar(10)ǰ4λΪţ6λΪкţкȡX3кšҲ˵ˮžǶʶһһʶΨһһˮһȥűھ;
òԡ۱ݼṹô仯䣬ֱɾˮŲŻʧˮűǸ࣬࣬ˮű֮ϵֻͨ X3 5Ӧģȫӳ䵽ݿģУγӦöݿһһӦ5ӦöĿϵͳԭеĶԣкܺõķװԺϢԡˮűһЩֵ࣬õġ
ͼ2 ϵʾͼ
塢 ϵݿЧ
ڹ·ϵͳУijϽݿƵյ춨ϵͳԣʹڳȫ濪Ч£
1.ݿṹʵOOP
ʵӦģݿȫӳ䣬ݿģͿȻֱӵģʵʵϵ·ûĵǰ硢ϵͳϵͳⲿܣ֧ϵͳܵڲݿ(ݽṹ)һһӦûߺݿάԱһµԽйͨ
رǶԶ˽·ҵijԱ˵ֽӦöӦݶװڶͳһеƷ˳ʵֵѶȣʹֻҪ֪ӹݼIJɣӦóͬԶദ̳ԱġԤȿõĸࡣ
2.ݿжԣά
ݿӦģһһӦ⣬ģûƶؼ̳еķϵõݿṹɸӱɵͲνṹм̳ĸӹϵһϾֲԭĽṹӶʹݿƻӰھֲΧұ·ϵͳͨݿճά
3.ʱݿʸߣ
ӳӦöʱϵӳ淶ܳһԶıӳ⣬ӦöһһӦġǿѹ淶ġһӦöӳĶһݿ˵ӦʱȣϵͳĿԲ漰IJ֡ΣֵĿԻֻӻɾģ¿ϲԭгԭп壬Ӷ˹˹Ѷȡ
ľõ
Ǵ۸ӵģѧ۵ķչҲԽԽӡȻ̽ۺͼĿǣÿĸӱľõġΪǸ¼Ҹ棺
1.
RDBMS ָ֧ӹϵǿûô趨϶ܴϰûʵ֡ʵǣһ𣬲ʹ RDBMSάһԸأҲʹݿӦøӻ˳ݿ⣬ʵϢƣѼ⸴ӻ
2. ʵ
ݿ˼·70Ǵʹ DBMSҪ֮һȻΪ˽ʡ2ֽڵĴ洢ռȫΪ֮ͷʹ2000һǼӲʱIJԽڼг۸Ϊ6GӲ̵ļ۸2000ԪϺ۾ 1996䷢һָԼ8000Ԫһµ۸ͿԹ20GҵӲ̡ʹ5ݵĿÿ¼ѹ40ַ࣬ϼҲ2Mʡ0.6ԪǮĴ̿ռ䡣
ѽļʱˣ⡢Ӧÿ١άݿṹõġֻҪԡһԲвЩ࣬Ϊǡ֮ʡɱ (Ӳɱ) õġ
3. Ϣ
ҪĻԭ֮һ֮ϢԽСԽãݿԽԽãΪӦóҪ֪ԽԽӡʹݿںл (ȸ) ķܶ࣬ϵľֲ⣬ DBMSĴ洢̡ȣݿĸӱϵװںرǷŵˣԽԸǶġ