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QuoteRef: ahmeR12_1991
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ThesaHelp:
references a-b
Topic:
heterogeneous database
Topic:
a single system image
Topic:
object-oriented databases
Group:
distributed database
Group:
database model
Topic:
object-oriented data types
Topic:
non-hierarchical classification and multiple classification
Topic:
data type by name or tags
Topic:
type inheritance as reuse
Topic:
non-exclusive data type
Topic:
unique names
Topic:
data type as a set of operations
Topic:
translation of data
Topic:
problem of assigning names
Topic:
meaning by use
Topic:
fundamental concepts such as type, attributes, relationships are all the same
Topic:
names as rigid designators
Topic:
names independent of objects
Reference
Ahmed, R., De Smedt, P., Du, W., Kent, W., Ketabchi, M.A., Litwin, W.A., Raffii, A., Shan, M.-C., "The Pegasus heterogeneous multidatabase system", Computer (IEEE), pp. 19-27, December 1991. Google
19 ;;Quote: Pegasus is a heterogeneous, multidatabase management system developed by Hewlett-Packard; object-oriented and relational
20 ;;Quote: Pegasus data model contains types, objects and functions; like Iris
20 ;;Quote: Pegasus types have unique names and represent collections of objects that share characteristics; interrelated by a DAG (multiple inheritance)
20+;;Quote: Pegasus functions on a given type are defined for all of its subtypes; objects are instances of a type and all of its supertypes
20 ;;Quote: Pegasus objects have unique ids and one or more types; may change types dynamically
20 ;;Quote: Pegasus functions for properties of, relations among, and computations on objects; arguments and results are typed
20+;;Quote: a Pegasus type can be characterized by the roles it plays in arguments and results of various functions
20 ;;Quote: a Pegasus schema makes a local data source appear as Pegasus database; maps between data models and query languages
21 ;;Quote: common concepts may be treated in different ways by different domains; e.g., different currencies
22 ;;Quote: a heterogeneous database may need a common view despite different definitions, algorithms, and units; users can specify the mappings
23 ;;Quote: similar concepts may be expressed differently across schemas; via relations, or attributes, or classes, or functions
23 ;;Quote: a single logical object may have different identifiers and different types in different databases; user needs to specify equivalences
ThesaHelp: references a-b (396 items)
Topic: heterogeneous database (6 items)
Topic: a single system image (30 items)
Topic: object-oriented databases (15 items)
Group: distributed database (6 topics, 188 quotes)
Group: database model (15 topics, 314 quotes)
Topic: object-oriented data types (29 items)
Topic: non-hierarchical classification and multiple classification (16 items)
Topic: data type by name or tags (29 items)
Topic: type inheritance as reuse (27 items)
Topic: non-exclusive data type (16 items)
Topic: unique names (57 items)
Topic: data type as a set of operations (38 items)
Topic: translation of data (26 items)
Topic: problem of assigning names (25 items)
Topic: meaning by use (58 items)
Topic: fundamental concepts such as type, attributes, relationships are all the same (37 items)
Topic: names as rigid designators (43 items)
Topic: names independent of objects (34 items)