Explain the distinction in meaning between edges in a DAG representing inheritance and a DAG representing object containment.
Answer to relevant QuestionsWhy do persistent programming languages allow transient objects? Might it be simpler to use only persistent objects, with unneeded objects deleted at the end of an execution? Explain your answer.If an object is createdwithout any references to it, howcan that object be deleted?Consider the E-R diagramin Figure, which contains composite, multivalued and derived attributes.a. Give an SQL: 1999 schema definition corresponding to the E-R diagram. Use an array to represent the multivalued attribute, ...Show, by giving a DTD, how to represent the books nested-relation from Section 9.1, using XMLConsider as shown below, and suppose that authors could also appear as top level elements. What change would have to be done to the relational schema?· · · similar PCDATA declarations for year, publisher, place, journal, ...
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