Feb 2001CSS/416: Module U1 Workshop 21 CSS/416 Data Design And Information Retrieval Workshop 2

Feb 2001CSS/416: Module U1 Workshop 22 Workshop 2 Outline Learning Team Presentations Preview of Workshop 3

Chapter 16 The Hierarchical and Network Data Models David M. Kroenke Database Processing © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 24 DL/I “Language for processing a database, implemented in the hierarchical database, IMS (Information Management System) from IBM” Page 453

Feb 2001CSS/416: Module U1 Workshop 25 DL/I Hierarchical Terms Field “smallest unit of data” Segment “groups of fields; nodes of the tree structure” Data base record “a collection of related segments; a particular tree structure” Data base “composed of database records” Page 453

Feb 2001CSS/416: Module U1 Workshop 26 DL/I Hierarchical Terms Data base description “how data base records are defined; set of assembly-language macro instructions” Root “first segment” Sequence field “one field in each segment used to order the occurrences of a given type” Page 453

Description of Data Base Page 455 Figure 16-7 © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 28 DL/I Hierarchical Terms Physical data base record (PDBR) “describes the data as it exists in data storage” Logical data base record (LDBR) “describes the data as they appear to the application program” Page 457

Hierarchies Page 456 Figure 16-8 © 2000 Prentice Hall

DL/1 Data Manipulation Commands Page 462 Figure © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 211 CODASYL DBTG Model Conference on Data Systems Languages Data Base Task Group CODASYL also developed standards for COBOL Complex and Incohesive Page 462

Feb 2001CSS/416: Module U1 Workshop 212 CODASYL DBTG Terms Schema “complete logical view of the database” Subschema “view of the database as it appears to an application program” Data structure description “maps schema records, fields, and relationships to physical storage” Page 462

Feb 2001CSS/416: Module U1 Workshop 213 CODASYL DBTG Terms User working area “contains database and control data for a particular user” Run-unit “the execution of a program by one of the users” Page 463

CODASYL DBTG Program/Data View Relationships Page 463 Figure © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 215 CODASYL DBTG Terms Data-item “a field that corresponds to an attribute (column)” Record “a collection of data-items” Set “a one-to-many relationship” Page 463

CODASYL DBTG Record Types Page 464 Figure © 2000 Prentice Hall

Two-Owner Record in Different Sets Page 466 Figure © 2000 Prentice Hall

Summary of Set Characteristics Page 467 Figure © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 219 CODASYL DBTG Data Manipulation Language FIND, GET FIND, MODIFY FIND, ERASE Page 470

Chapter 17 Object-Oriented Database Processing David M. Kroenke Database Processing © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 221 Object-Oriented Programming OOP; a way of designing and coding programs which views programs as sets of data structures that have both data elements and program instructions Page 483

Feb 2001CSS/416: Module U1 Workshop 222 OOP Terminology Encapsulated complete in itself Encapsulated structure an OOP object that has both attributes (properties) and methods Interface external appearance of an object Page 484

Feb 2001CSS/416: Module U1 Workshop 223 OOP Terminology Implementation “the encapsulated internals of an object” Inheritance “automatically assuming the attributes and methods of another object at a higher class” Polymorphism “situation in which one name can be used to invoke different functions” Page 484

Feb 2001CSS/416: Module U1 Workshop 224 OOP Terminology Object Class “the logical structure of an object (name, attributes, methods)” Object Class Library “a group of object classes” Objects “instances of objects” Transient vs. Persistent “volatile vs. permanent” Page 485

Sample Objects, Methods, and Attributes Page 486 Figure 17-2 © 2000 Prentice Hall

Sample Object Data Structures Page 489 Figure 17-4 © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 227 Swizzling “The process of transforming permanent identifiers into in-memory addresses” Page 489

Tasks for Object Persistence Page 489 Figure 17-5 © 2000 Prentice Hall

Application Development Work for Object Persistence Page 492 Figure 17-8 © 2000 Prentice Hall

ODBMS Advantages and Disadvantages Page 493 Figure 17-9 © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 231 ODBMS Standards SQL3 “an extension to SQL92 that includes support for OODBMS” Abstract data type “ADT; user- defined structure that is equivalent to an OOP object” Page 495

Feb 2001CSS/416: Module U1 Workshop 232 ODMG-93 “Object Data Management Group; a consortium of object database vendors and experts that developed a definition of interfaces for object data management products in 1993” Page 500

Key Elements of the ODMG Object Model Page 501 Figure © 2000 Prentice Hall

ODMG Relationship Operations Page 502 Figure © 2000 Prentice Hall

Feb 2001CSS/416: Module U1 Workshop 235 Data Structures C102 A103 D-00 B Linked List (100)(101)(102)(103) Head

Feb 2001CSS/416: Module U1 Workshop 236 Data Structures Indexed Ames101 Boyce103 Jones102 Smith100 SmithAnaheim AmesSanta Ana JonesIrvine BoyceCosta Mesa

Feb 2001CSS/416: Module U1 Workshop 237 Data Structures AEAlex BEBetty CACarl DDon B-tree Root BLJI AIBLCAJI AIAlice BLBillCTCathy JIJill Value or pointer