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Pt2520 Lab 5.1

Decent Essays
Questions for HW 5
1. You see an announcement for a job as a "Database Administrator" for a large corporation but are unclear about what this title means. Research this on the Web and obtain specific job requirements. (Must be at least a paragraph about this. Minimum 5-7 sentences.)
Database administrators must create ways to store, analyze, utilize, and organize data. A DBA develops computer databases based on user needs and migrate data from old systems to new systems. DBA’s ensure that business data is accurate, available and secure. The specific requirements for a DBA position include having a minimum of a bachelor’s degree in Computer Science and expert knowledge on SQL. SQL is the standard language for relational database management systems. For this position one must also be an expert with Microsoft SQL Server mirroring and replication.
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Describe the three types of relationships in a relational database.
One-to-one relationships are between two entities in which an instance of one entity can be related to only one instance of a related entity. A row in a given table would have only one match in a row in another table. Therefore there can only be a one-to-one match.
A one-to-many relationship is the most common relationship and is between two entities in which an instance of one entity can be related to many instances of a related entity. For this relationship a row in table C can have many matches in table A, but a matching row in table A can have only one match in C. Most relational databases are constructed from this type of relationship.
A many-to-many relationship is between two entities in which an instance of one entity is related to many instances of another and one instance of the other can be related to many instances of the first entity. For example table A could have many pairs in table B. This relationship goes both ways with no constraints. Removing a many-to-many relationship, it will allow for a more accurate and consistent
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