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Explain Record Based Logical Models?
Record-Based logical Models: Also define data at the conceptual and view levels. Unlike object-oriented models, are used to state overall logical structure of the database, and gives a higher-level description of the implementation. Named so since the database is structured in fixed-format records of various types. Each record type defines a fixed number of fields, or attributes. Each field is commonly of a fixed length (this simplifies the implementation). Record-based models do not involved a mechanism for direct representation of code in the database. Separate languages related along with the model are used to express database queries and updates. The three most widely-accepted models are the relational, network, and hierarchical.
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About Attribute inheritance
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Determine Which is not a consequence of concurrent operations? Ans: Update anomaly.
Benefits and limitations
In an E-R diagram an entity set is represent by? In an E-R digram entity set is represted by rectangle.
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Entity types that do not have any key attribute, and therefore cannot be identified independently, are known as weak entity types. A weak entity can be recognized uniquely only by
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