Group:
data type
Topic:
abstraction
Topic:
data-driven design
Topic:
database entities
Topic:
database schema
Topic:
entity-relationship database model
Topic:
existence of database entities
Topic:
fact-based analysis for database design
Topic:
software models of reality
Topic:
programming with data
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Summary
A database is a partial model of reality. It represents a set of views, held by a community for users, on how they retrieve and process information. This model should be accurate and at the same time simple. There should be a correspondence between entities and actual objects and between values and actual properties. (cbb 1/90)
Subtopic: model of real world 
| Quote: a database models a small, finite subset of the real world [»kentW_1978]
| | Quote: an information system is a model of the real world [»borgA1_1985]
| | Quote: a database represents a set of views of reality held by a community; to share knowledge, data must have a precise and unambiguous interpretation [»kimuTD7_1985]
| | Quote: correspondence between database model and real world is rather ad hoc [»kentW_1978]
| | Quote: a database models the way people process information about reality [»kentW_1978]
| | Quote: a database model is how users get to know and agree upon the meaning of data items [»kentW_1978]
| | Quote: even though a database doesn't model reality, it is still useful [»kentW_1978]
| | Quote: modern systems interact with many people for many purposes, need correct assumptions [»kentW_1978]
| | Quote: design the enterprise schema as an abstract representation of the real world before designing the storage schema [»chenPP_1977]
| | Quote: databases use extension (database entities) and intension (database constraints) [»sowaJF_1984]
| | Quote: Agenda categories become the words of a language for describing information and its interrelationships [»kaplSJ7_1990]
| | Quote: data structures model the problem environment; good foundation from program structures [»jackMA_1975]
| | Quote: events model the interaction between an enterprise and its environment
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Subtopic: Jackson System Design
| Quote: JSD first models the external events, their associated attributes and mutual orderings [»cameJR2_1986]
| | Quote: events are the basic medium for JSD modeling; directly visible, atomic occurrence [»cameJR2_1986]
| | Quote: JSD defines an entity in terms of its actions and relevant events; e.g., a BOOK is ACQUIRED, CLASSIFIED, LENT, etc. [»cameJR2_1986]
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Subtopic: conceptual modeling
| Quote: in conceptual modeling, objects correspond one for one with real entities [»borgA1_1985]
| | Quote: the real world consists of entities and relationships; basis for entity-relationship model [»chenPP3_1976]
| | Quote: quantities in the model system usually corresponds to a property of a component of the referent system [»handP_1981]
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Subtopic: time-varying
| Quote: the conceptual schema of an information system varies over time [»theoCI3_1991]
| | Quote: databases may model reality but they ignore time-varying aspects, e.g. historical queries and trend analysis [»snodR9_1986]
| | Quote: conventional databases are a snapshot of the current state; may be somewhat out-of-date [»snodR9_1986]
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Subtopic: limitations
| Quote: the data model of a library may use separate objects for two different books, or two copies of the same book, or a single copy at different times [»holtAW_1979]
| | Quote: a model theory should permit incomplete and inconsistent worlds; need to localize inconsistencies [»sowaJF_1984]
| Quote: structure arises out of the grouping of similar items and intergroup relationships; and not from hypertext links between items
[»kaplSJ7_1990]
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Related Topics
Group: data type (34 topics, 730 quotes)
Topic: abstraction (62 items)
Topic: data-driven design (41 items)
Topic: database entities (12 items)
Topic: database schema (29 items)
Topic: entity-relationship database model (22 items)
Topic: existence of database entities (19 items)
Topic: fact-based analysis for database design (15 items)
Topic: software models of reality (24 items)
Topic: programming with data
(16 items)
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