Adabas veri tabanı, natural programlama dili ve kargo rezervasyon projesi

Abstract

ADABAS(Adaptab1e Data Base System) software is a data base management system. it can be deflned as a data spool where ali of the datas are stored in as data base f11 es. AOABAS data base system provides security and relatlons among the datas 1n thls data spool. ADABAS data base 1s on the disks. ADABAS has three components: 1 Data Storage, 2 Associator, 3 Uork, Natural which is a fourth generation language is öne of the most common environment to access ADABAS on-line. Natural runs under the CICS (Customer Information Control System). Therefore CICS has to be opened to access ADABAS on-line. Nucleus (is a Software AĞ. product) is an interface providing data flow between ADABAS and Natural[3]. - xi - DISADVANTAGES OF DATABASE PROCESSING A majör disadvantage of database processlng 1s that 1t is expens1ve. Önce the database is iırıplemented, operating costs for some systems w1ll be hlgher, S@quent1a1 processlng of payroll, for example, w111 never be done as fast in the database envlronment. There simply is too much overhead. Another majör disadvantage 1s that database processlng tends to be complex. Large amounts of data in many di fferent formats can be interrelated in the database. Both the database system and the application programs must be able to process these structures. Thls means more sophisticated programming. Application system design may take longer, and highly gualified systems and programming personnel are requ1red. Backup and recovery are more difficult in the database envlronment. Th1s is because of increased comp1exity and beca- use databases are often processed by several user concurrently. Determining the exact state of the database at the time of fail üre may be a problem. Given that, it may be even more difficult to determine what should be done next. Even the fali üre of just öne application program may pose serious problems. If program A modifies several records and then fail s, 1t may be necessary to rol l back (ör elimınate) A's modificatlons. If this Is done, program B, which read the records after modification, but before they were rolled back, may have Invalld data. A final disadvantage is that integration, and hence centralization, increases vulnerability. A failure in öne component of an integrated systems can stop the entire system. This Is espedally critical 1f, as Is usually the case, the operation of the user organizati on depends on the database. DATABASE ENVIRONNENT Three components are involved in database processlng: the user, ör his application programs, system support software, and database itself. The application Is developed for the user who deddes the content of the database, deflnes the relatlon- ship betueen data items, and causes modification and retrieval of data items. System support software includes a communication processor, a database management system, and the operatrng system. These systems operate together to process the database in accordance w1th the user's conunands. Finally, the database must contain ali the data necessary to satlsfy the user's information needs.. x - ADABAS(Adaptab1e Data Base System) software is a data base management system. it can be deflned as a data spool where ali of the datas are stored in as data base f11 es. AOABAS data base system provides security and relatlons among the datas 1n thls data spool. ADABAS data base 1s on the disks. ADABAS has three components: 1 Data Storage, 2 Associator, 3 Uork, Natural which is a fourth generation language is öne of the most common environment to access ADABAS on-line. Natural runs under the CICS (Customer Information Control System). Therefore CICS has to be opened to access ADABAS on-line. Nucleus (is a Software AĞ. product) is an interface providing data flow between ADABAS and Natural[3]. - xi - DISADVANTAGES OF DATABASE PROCESSING A majör disadvantage of database processlng 1s that 1t is expens1ve. Önce the database is iırıplemented, operating costs for some systems w1ll be hlgher, S@quent1a1 processlng of payroll, for example, w111 never be done as fast in the database envlronment. There simply is too much overhead. Another majör disadvantage 1s that database processlng tends to be complex. Large amounts of data in many di fferent formats can be interrelated in the database. Both the database system and the application programs must be able to process these structures. Thls means more sophisticated programming. Application system design may take longer, and highly gualified systems and programming personnel are requ1red. Backup and recovery are more difficult in the database envlronment. Th1s is because of increased comp1exity and beca- use databases are often processed by several user concurrently. Determining the exact state of the database at the time of fail üre may be a problem. Given that, it may be even more difficult to determine what should be done next. Even the fali üre of just öne application program may pose serious problems. If program A modifies several records and then fail s, 1t may be necessary to rol l back (ör elimınate) A's modificatlons. If this Is done, program B, which read the records after modification, but before they were rolled back, may have Invalld data. A final disadvantage is that integration, and hence centralization, increases vulnerability. A failure in öne component of an integrated systems can stop the entire system. This Is espedally critical 1f, as Is usually the case, the operation of the user organizati on depends on the database. DATABASE ENVIRONNENT Three components are involved in database processlng: the user, ör his application programs, system support software, and database itself. The application Is developed for the user who deddes the content of the database, deflnes the relatlon- ship betueen data items, and causes modification and retrieval of data items. System support software includes a communication processor, a database management system, and the operatrng system. These systems operate together to process the database in accordance w1th the user's conunands. Finally, the database must contain ali the data necessary to satlsfy the user's information needs.. x - ADABAS(Adaptab1e Data Base System) software is a data base management system. it can be deflned as a data spool where ali of the datas are stored in as data base f11 es. AOABAS data base system provides security and relatlons among the datas 1n thls data spool. ADABAS data base 1s on the disks. ADABAS has three components: 1 Data Storage, 2 Associator, 3 Uork, Natural which is a fourth generation language is öne of the most common environment to access ADABAS on-line. Natural runs under the CICS (Customer Information Control System). Therefore CICS has to be opened to access ADABAS on-line. Nucleus (is a Software AĞ. product) is an interface providing data flow between ADABAS and Natural[3].