Saturday, September 7, 2019
Visualizing Complexity Essay Example | Topics and Well Written Essays - 500 words
Visualizing Complexity - Essay Example The record types are organised in the form of a rooted tree. However, in network model, multiple branches emanate from a single or more nodes (Lima 86). It can be likened to several trees sharing branches. Consequently, the hierarchical model can be said to support one-one relationships and one-to-many relations in contrast to the network data model that supports many to many relationships. The hierarchical model supports a data structure whereby there is a parent-child relationship in contrast to the network model whereby a record can have many parents as well as many children. Whereas the network model uses CODASYL the hierarchical model is not a provider of any independent, stand-alone query interface. The commonality among the models, the hierarchical model and network database model is that in both of them retrieve algorithms are complex and systematic (Lima 109). The hierarchical data model has an insertion a normally whereby one cannot retrieve information on a child who has no parent in contrast to the network model that has no anomalies. In addition, the network model is free from update anomalies as a result of a single occurrence in each set. The hierarchical data model, however, has multiple occurrences of child records, which causes inconsistency problems during the update operations. In hierarchical model, data integrity is based on parent-child relationship and the deletion of parent results. In the deletion of child records, the network model is free from all the deletion anomalies because information is stored in a different table, which further enhances its efficiency. In the network database model, a child entity can have many parents and can be visualised as several inverted trees interconnected by branches contrary to the single inverted trees characterised by branches in the hierarchical model. Folksonomy refers to a classification system derived from the methodology and practise of collaboratively, creating,
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