Deductive database

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Deductive database
Active database

• Group 7
• Alexander Tan Thiam Ong WGA060040
• Beh Kee Lim
  WGA060023
• Qi Han
  WGA060026
• Yang Lina
  WGA060004
• Zhai Chunchao
  WGA060031

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Deductive database

• Introduction
• A deductive database system is a database system
  which can make deductions (ie infer additional
  rules or facts) based on rules and facts stored
  in the (deductive) database.
• Deductive Databases have been the focus of
  intense research, which has brought dramatic
  advances in theory, systems and applications.
• Feature of deductive databases capability of
  supporting a declarative, rule-based style of
  expressing queries and applications on databases.

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Deductive database

• Deductive database systems
• Mainly deal with rules and facts.
• Use a declarative language (such as prolog) to
  specify those rules and facts.
• Use an inference engine which can deduce new
  facts and rules from those given.

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Deductive database

• Deductive Database Languages---prolog and datalog
• Prolog is a logic programming language.
• "programming in logic ". Expression of logic
  instead of
• carefully specified instructions on the
  computer.
• subset of Planner .
• Datalog is a query and rule language for
  deductive databases that syntactically is a
  subset of Prolog.

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Deductive database

• What is the rules and facts?
• The deductive database field has had close
  links with the logic programming community, and
  much of the development of deductive database
  systems has centered around languages based on
  Horn clauses.

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Deductive database

• This class of formulas forms the basis of PrologA
  
• Horn clause is generally written as
• p(t) - ql(tl), . . . , qn(n)
• where p and ql, qn are predicate
  letters, n _gt 0, and all variables that occur in
  the terms t, t-l,. , tn are considered
  universally quantified at the front of the
  clause.
• Note that n may be 0, in which case we refer to
  the clause as a fact. Otherwise, we refer to the
  clause as a rule.

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Deductive database

• Declarative Programming
• two important ways
• 1. The order in which goals are written in the
  rules does not determine their actual execution
  order, which is controlled by the system rather
  than the programmer.
• 2. The selection between forward-chaining and
  backward-chaining execution is automatic--it is
  done by the system, rather than the programmer.

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Deductive database

• Systems and Applications
• most deductive database systems position
  themselves as extensions to and improvements of
  existing relational databases rather than as
  their replacement.
• A second ingredient found critical in many
  applications is an open and extensible
  architecture.

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Deductive database

• Future Directions
• We are looking forward to a new generation of
  deductive database systems that embody these new
  advances, along with the know-how acquired in
  building the first generation of research
  prototypes.

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Active Database

• Introduction
• Mechanisms that enable them to respond
  automatically
• Considerable effort has been directed towards
  improving understanding
• Review
• Database systems are beginning to be applied
  to domains that involve more complex information
  processing

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Active Database

• What is it ABOUT
• Over the past few years, the topic of active
  databases has become an important area of
  research .
• Many DBMSs have addressed support for
  event-condition-action (ECA) rule in databases.
• Current practice Data-driven oriented active
  database model

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• ADBMS

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Active Database

• The progress of the research
• At the point of function ,an active database
  system (ADBS) is consisted with traditional
  database system , event-driven knowledge base
  (EB) and events monitor(EM).
• ADBS DBS EB EM
• EB is a group of event-driven by the knowledge
  pool
• EM is a monitoring module monitored if the
  incident has happened in EB

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Active Database

• Traditional ADBMS has many problems in the
  practical application, such as it has a long and
  difficult period of development, and it does not
  rapidly use of the data gaps identified in
  history

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Active Database

• Component-based active database (CAB)
• Directly use of the database which has been
  created to complete the data, the sharing to and
  the other functions .
• Add an intermediate layer components in the
  data link layer to supervise the changing of the
  system, and then transfers those to the EM
  immediately.
• When Monitor found that the incident
  occurred when a systematic definition of the
  conditions for automatic matching, if successful
  match, trigger corresponding moves on
  implementation

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Active Database

• 2 Based on dynamic fuzzy logic (DFL) active
  database
• Based on dynamic fuzzy logic active database
  system (DFADBS) is consisted with a Dynamic Fuzzy
  Database System (DFDBS), DF Event-driven Base
  (DFEB) and DF Event Monitor (DFEM) .
• DFADBSDFDBSDFEBDFEM

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Active Database

• WHEN ltDF Eventgt
• IFltDF Condition 1gtTHENltDF Action 1gt
• IFltDF Condition ngtTHENltDF Action ngt(n1)
• Once the "incident" occurred, the computer
  would take
• the initiative to trigger the implementation
  of the IF-THEN rules later, until the enforcement
  lasts.

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Datalog

• A query and rule language for deductive databases
  
• Subset of Prolog
• Facts state info that are true, eg
• Rules state info that are true if certain
  condition apply, eg

woman(mia). listensToMusic(mia).happy(yolanda).
playsAirGuitar(mia)  - listensToMusic(mia).plays
AirGuitar(yolanda) - listensToMusic(yolanda).lis
tensToMusic(yolanda)- happy(yolanda).
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Datalog

• Query, eg
• Return yes, because the fact is stated
• Both queries above return no, because the fact
  is unknown
• Return yes, because the yolanda play guitar if
  listens to music, yolanda listens to music if
  happy, and according to the fact, yolanda is
  happy

?- woman(mia).
?- woman(yolanda). ?- student(mia) .
?- playsAirGuitar(yolanda).
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Systems Implementing Deductive DB

• Bddbddb (BDD-Based Deductive DataBase)
• ConceptBase
• DES (Datalog Educational System)
• DLV
• XSB

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Deductive DB Implementation

• Using DES
• Family Tree System

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Deductive DB Implementation

• Facts Rules

father(tom,amy). father(jack,fred). father(tony,ca
rolII). father(fred,carolIII). mother(graceI,amy).
mother(amy,fred). mother(carolI,carolII). mother(
carolII,carolIII). parent(X,Y) -
father(X,Y). parent(X,Y) - mother(X,Y). ancestor
(X,Y) - parent(X,Y). ancestor(X,Y) -
parent(X,Z), ancestor(Z,Y).
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Deductive DB Implementation

• Starting DES

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Deductive DB Implementation

• Consulting Datalog program file (load facts
  rules)

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Deductive DB Implementation

• Querying descendants of tom

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Deductive DB Implementation

• Querying parents of amy

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Deductive DB Implementation

• Insert john as son of fred and carolIII

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Deductive DB Implementation

• Remove john

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Active DB Implementation

• Using Oracle9i

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Active DB Implementation

• Making an HTTP call from PL/SQL to activate a
  Java Servlet
• Using advanced queuing (AQ) to activate a
  message-driven bean (MDB)
• Using AQ to notify a Java client application of
  changes in the database

declare    t_result varchar2(4000)begin   
-- do something    t_result
utl_http.request('http//www.myweb.com/myservlet?m
yparammydata')    -- do somethingend