Writing Resources
This paper is a pioneer work by in relational database systems concepts of which are used to develop a sound database model even today When we study a good database model the key characteristic that defines the model is the non alteration of activities of users and application programs when changes are made to internal or external representation of data The Paper talks about the existing database models until 1970 its drawbacks by considering the problem of data dependency and subsequent solutions to fix them Ordering dependency resulted in the failure of an application program as the program failed to differentiate between the stored ordering and the presentation ordering of the data due to the changes made to the data stored indexing Indexing dependency slowed down during addition and deletion operations Since indexing is redundant indices needed to be created and destroyed accordingly The problem of Access Path dependency could be handled by not making the path as obsolete only when all the application programs using the paths have become obsolete The relational view of the data is presented well in the next section of the paper with its characteristics an array representation of relations where each row being distinct represents an n tuple in relation R and its ordering is not necessary but the ordering of columns is important as they represent the domains on which R is defined It also solves the problem which one can encounter with identical domain names and time varying relations With higher order unique domain names and relations are domain unordered relationship
