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Slide 2 Data Structure Concepts Record Collection of field values Grouped as record types Parent-Child Relationships 1 :N Occurrence : ONE parent and zero or more children Notation : (parent record type, child record type) Slide 3 Hierarchical Diagram Department DNAMEDBNUMBERMGR_IDMGRSTARTDATEPNAMEPNUMBERPLOCATION ProjectEmployee NAMEIDADDRESSSTARTDATE (Department, Employee)(Department, Project) Slide 4 Properties of Hierarchical Schema Root record type Top of tree Not a child of any other record type Parent record type can have multiple children Child record types are ordered A record type that does not participate as a parent record type is called a leaf Slide 5 Occurrences of Parent-Child Relationships Research Department Administration Department (Department, Employee) Smith Wang English (Department, Project) ProductX ProductY ProductZ (Department, Employee Jones, Wallace Kirk (Department, Project) NewBenefits Computerization Slide 6 Data Manipulation Language Record -at- a- time language GET (FIRST | NEXT) [WHERE ] GET (FIRST|NEXT) PATH [WHERE ] Slide 7 Data Manipulation Language INSERT DELETE REPLACE Slide 8 Slide 9 Data Structure Concepts Record Collection of related data values Record Types Classified into record types Store the same type of information Data Item Data name and format Relationships are represented as links Slide 10 Set Type Diagram Department DNAMEDBNUMBERMGR_IDMGRSTARTDATE Student NAMEIDADDRESSSTARTDATE Owner Record Type Member Record Type Major_Dept Slide 11 Member Records Ordered Think of as linked CS Department Dannelly Foster Olsen Thacker Slide 12 M: N Relationships Employees can work on more than one project E1 E2 E3 E4 P1 P2 P3 P4 W1 W2 W3 W4 W5 W6 W7 Slide 13 M: N Relationships E1 P1 E2 E3 E4 w1 w2 w3 w4 w5 w6 w7 P4 P3 P2 P4 Slide 14 Data Manipulation Language FIND (FIRST | LAST | PRIOR | NEXT) GET Record Updates STORE ERASE MODIFY Set Update CONNECT DISCONNECT RECONNECT Slide 15 Slide 16 Active Database Event-based rule processing. The behavior of an active database is accomplished through a set of ECA-rules (Event-Condition-Action rules) related with the database. An active database gains its power from the array of events it can respond to and the type of actions it can perform in response. Active databases support the creation of triggers which fire when certain operations occur on the database. http://it.toolbox.com/wiki/index.php/Active_Database Slide 17 Fundamental features Events Primitives for database state changes Monitor retrievals, time-related, application defined, etc Conditions Database predicate or query Returns a truth value Actions Arbitrary data manipulation program Slide 18 Slide 19 Temporal Database Concepts Encompass all database apps that require some aspect of time when organizing information. Example: What is Bobs salary history? Provide the salary and department history for all employees. NameSalaryTitleStartStop Bob1000Tech101/12/0906/01/09 Bob1000Tech201/12/0906/01/09 Bob300Tech306/01/0901/01/10 Slide 20 Time is considered to be an ordered sequence of points in some granularity. chronon Represent as an Age: requires a reference starting point Period: nt time via a time period Slide 21 Slide 22 Slide 23 Slide 24 Slide 25 Slide 26 Slide 27