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14 Cards in this Set
- Front
- Back
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What is a hierarchical database structure?
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-early DBMS structure
-records in tree structure -relationships are one to many |
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What is a network database structure?
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-used in some mainframe DBMS packages
-relationships are many to many |
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What is a relational database structure?
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-Data elements are stored in tables
-Row represents a record; column is a field -Can relate data in one file with data in another, if both files share a common data element |
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What are the pros and cons of each database structure? Which one is most commonly used today?
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hierarch: P = works for structured transactions. C = cant handle many to many
Network: P = more flexible than H. C = cant handle ad hoc requests Relational(best): P = handles ad hoc, easy to work & maintain. C = not as efficient as other 2 |
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What is a record? An attribute? an entity?
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: row in a table (grouping all fields of attributes of entity)
: a thing in record (characteristic/quality) : person, place, object |
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What does OLAP stand for?
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Online Analytical Processing
-it is part of Multidimensional structure |
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What is encapsulation? Inheritance?
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: combine data and operations
: new objects created by replicating characteristics of parent objects *apart of object-oriented structure |
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What is DDL? What is metadata?
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: data definition language used to develop & specify data contents, relationships, & structure (used by DBA)
: data about data ( apart of data dictionary) |
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What is a data dictionary?
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-metadata
-database of data definitions -database maintenance, security, requirements and descriptions for data and end users |
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What is an operational database?
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-stores info on business's operations and processes
-AKA: subject area/transaction/production databases -EX- inventory & HR |
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What is a distributed database?
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-spreads data to mult. sources
-improves performance, protection, & access -bad for data accuracy |
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What is the primary purpose of a data warehouse?
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-having a central source for analysis, research, etc.
-info needs to be cleaned, transformed, & cataloged first |
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What is a data mart?
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Subsets of data that focus on specific aspects of a company (department or business process)
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What is SQL?
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Structured Query language
-asking info from data -found in DBMS packages |
