DATABASES

Databases

Databases

Requirements for Scheduling Process

A schedule is a convenient way to manage your time. A schedule must be planned and designed according to the nature of the database to make sure it is correct and to avoid the need to work many changes after its inception. One factor that significantly influences the scheduling process is the intent of an application program toward the databases that it uses (Becker 2003). Intent is determined by the intent that is associated with the PSB to be scheduled. At initial selection, this process involves bringing the intent list into the EMS control region if it is not already resident (preloaded). If the analysis of the intent list indicates a conflict in database usage with a currently active program in another dependent region, the rescheduling process for this transaction code is ended (Dhawan 2010). The database intent of a program at scheduling time is determined by the PROCOPT— parameters in the database PCBs in the PSB (Talia, Bilas & Dikaiakos 2007). At any point during scheduling, several parts of the database might require refinement (through additional constraint posting) to produce a complete specification of the final schedule (Talia, Bilas & Dikaiakos 2007).

Centralized databases are characterised by centralized control. In contrast, distributed databases are characterized by a hierarchical control structure controlled by a common database administrator. This administrator has the overriding responsibility managing the whole database. In case of local database, respective accessible databases hold the administration rights.

Data independence is also important requirement for scheduling within DDBMS and DBMS. Data independence represents the actual organization or data transparency of the programmer of DBMS application. Centralized DBMS applications are based on conceptual view of the data, a view which is also referred to as conceptual schema. The basic advantage of data independence is that programs are not affected by modifications in the physical structure or organization of data. Moreover, Systems Database Managers are a type of software very specific, dedicated to provide an interface between databases and applications that use it. It consists of a language for data definition, a data manipulation language and a query language. In texts that address this issue, or related issues are mentioned DBMS and DBMS terms, both equivalent and acronyms, respectively, of System Database Manager and Database Management System, the English expression. In addition, data integrity occurs when there throughout the system procedures for uniform data validation.

Scheduling Pros and Cons

The schedule determines ...