Term
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Definition
| a technique for organizing and documenting a system's data. Sometimes called a database modeling. |
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Term
| entity-relationship diagram (ERD) |
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Definition
| a data model utilizing several notations to depict data in terms of the entities and relationships described by that data. |
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Term
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Definition
| entity = a class of persons. places, objects, events, or concepts about which we need to capture and store data. |
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| a single occurrence of an entity. |
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Definition
| a descriptive property or characteristic of an entity. Synonyms include element property, and field. |
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Definition
| an attribute that consists of other attributes. Synonyms in different data modeling languages are numerous: concatenated attribute, composite attribute, and data structure. |
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Definition
| a property of an attribute that identifies what type of data can be stored in the attribute. |
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Definition
| a property of an attribute that defines what values the attribute can legitimately take on, |
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Definition
| the value that will be recorded if a value is not specified by the user. |
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Term
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Definition
| an attribute, or a group of attributes, that assumes a unique value for each entity instance. It is sometimes called an identifier. |
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Definition
| a group of attributes that uniquely identifies an instance of an entity. Synonyms include composite key and compound key. |
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Definition
| one of a number of keys that may serve as the primary key of an entity. Also called candidate identifier. |
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Definition
| a candidate key that will most commonly be used to uniquely identify a single entity instance. |
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Term
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Definition
| a candidate key that is not selected to become the primary key. A synonym is secondary key. |
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Term
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Definition
| an attribute(s)whose finite values divide entity instances into subsets. Sometimes called inversion entry. |
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Term
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Definition
| a natural business association between one or more entities. |
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Term
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Definition
| the minimum and maximum number of occurrences of one entity that may be related to a single occurrence of the other entity. |
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Definition
| the number of entities that participate in a relationship. |
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Definition
| a relationship that exists between instances of the same entity. |
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Definition
| an entity that inherits its primary key from more than one other entity. |
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Definition
| a primary key of an entity that is used in another entity to identify instances of a relationship. |
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Definition
| a data entity that derives one or more attributes from another entity, called the parent. In a one-to-many relationship the child is the entity on the "many" side. |
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Term
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Definition
| a data entity that contributes one or more attributes to another entity, called the child. In a one-to-many relationship the parent is the entity on the "one" side. |
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Term
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Definition
| a relationship where many instances of an entity are associated with many instances of another entity. Also called many-to-many relationship. |
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Term
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Definition
| a concept wherein the attributes that are common to several types of an entity are grouped into their own entity. |
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Definition
| an entity whose instances store attributes that are common to one or more entity subtypes. |
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Term
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Definition
| an entity whose instances may inherit common attributes from its entity super type |
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Definition
| a data model for a complete, single information system. |
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Definition
| a data model that includes entities and relationships but no attributes. |
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Definition
| a data model that includes entities and relationships with precise cardinalities resolving non-specific relationships into associative entities, and also including primary and alternate keys. |
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Term
| fully attributed data model |
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Definition
| a data model that includes all entities, attributes, relationships, subsetting criteria, and precise cardinalities. |
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Definition
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Definition
| a business code whose structure communicates data about an entity instance. |
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Definition
| a technique used to improve a data model for implementation as a database. |
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Definition
| a data analysis technique that organizers data into groups to form nonredundant, stable, flexible, and adaptive entities. |
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Term
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Definition
| an entity whose attributes have no more than one value for a single instance of that entity. |
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Term
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Definition
| an entity whose non-primary-key attributes are dependent on the full primary key. |
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Definition
| a relationship in which the parent entity's key is also part of the primary key of the child entity. |
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Term
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Definition
| a relationship where many instances of an entity are associated with many instances of another entity. Also called many-to-many relationship. |
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Definition
| an entity whose non-primary-key attributes are not dependent on any other non-primary-key attributes. |
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Term
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Definition
| when the value of a nonkey attribute is dependent on the value of another nonkey attribute other than by derivation. |
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Term
| data-to-location-CRUD matrix |
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Definition
| a matrix that is used to map data requirements to locations. |
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