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10 Cards in this Set
- Front
- Back
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database
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structured collection of records or data that is stored in coputer system
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relational model
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basic data structre; table with rows repping entities and columns repping attrinutes of entity (name, address, etc)
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primary key
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column that IDs a unique row (horizontal) in a table
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compound key
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group of columns that ID's a unique row in a table (horiz)
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foreign key
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key of diff or foreign table
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normalization
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best practices designed to eliminate data duplication
prevents data manipulation and loss of dtat integrity process of concerting a poorly structure table into two or more well-structured tables to eliminate data duplication goal is to construct tables so that each one ahas a single relation or theme |
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structured query language
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international standard language for processing databases
read data insert data modify data delete data |
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relational operations (select, project, join)
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select: creates subsets of data of all recods that meet stated criteria
project: creates subsets of columns join: combines relational tables to provide users with more info than available in individual tables |
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concurrency controls
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method used to ensure database transaction are ecectuted in a safe manner and follow ACID rules
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are are the ACID rules?
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atmocity: either all tasks in transactio are done or none of them are
consistency: every transac must preserce integrity constraints isolation: two simultaneous transacts cannot interfere with each ohter durability: completed transactions cannot be aborted later or have results discarded |
