Heterogenous data base


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Heterogenous data base

  1. 1. Heterogeneous Database System Presentation Report COMSATS INSTITUTE OF INFROMATION TECHNOLOGY PARKROAD CHAKSAHZAD CAMPUS ISLAMABAD REPORT OF DATABASE PRESENTATION Group Members: (SP12-BCS-089) Hanzla Akram Submitted To: Haq Nawaz (SP12-BCS-088) Sir Tehseen Riaz Abbasi Submisson Date: 014 December 2013 1 Database System 271
  2. 2. Heterogeneous Database System Presentation Report Heterogeneous Database Definition “A Heterogeneous Database System is an automated (or semi-automated) system for the integration of heterogeneous, disparate database DBMS to present a user with a single, unified query interface. Heterogeneous database systems (HDBS) are computational models and software implementations that provide heterogeneous database integration” Introduction and Discription There are two main types of DDBS one is Homogeneous Database System and other one is Heterogeneous Database System. Our report focus is on Heterogeneous Database System. HDBS comprises a software layer (integration layer)and multiple DBSs and/or file Systems to be integrated. Users can transparently access the integrated DBSs and/or file systems via the interface provided by the integration layer. Defines a global data model Supports a Data Definition Language (DDL)Supports a Data Manipulation Language (DML)Distributed Transaction Management Transparent integration of the underlying, disparate DBS. The integrated, local DBSs are autonomous and can also be used as stand-alone systems. Local applications are unchanged and unknown to the HDBS. The transformation of existing local databases to meet diverse application needs at the global level is performed through a four-layered procedure that stresses total schema integration and virtual integration of local databases. The proposed methodology covers both schema integration and database integration, and uses a four-layered schema architecture (local schemata, local object schemata, global schema, and global view schemata) with each layer presenting an integrated view of the concepts that characterize the layer below. Mechanisms for accomplishing this objective are presented in theoretical terms, along with a running example. Object equivalence classes, property equivalence classes, and other related concepts are discussed in the context of logical integration of heterogeneous schemata, while object instance equivalence classes and property instance equivalence classes, and other related concepts are discussed for data integration purposes. The proposed methodology resolves naming conflicts, scaling conflicts, type conflicts, and level of abstraction, and other types of conflicts during schema integration, and data inconsistencies during data integration In a heterogeneous distributed database system, at least one of the databases is a nonOracle system. To the application, the heterogeneous distributed database system appears as a single, local, Oracle database. The local Oracle database server hides the distribution and heterogeneity of the data. 2 Database System 271
  3. 3. Heterogeneous Database System Presentation Report The Oracle database server accesses the non-Oracle system using Oracle Heterogeneous Services in conjunction with an agent. If you access the non-Oracle data store using an Oracle Transparent Gateway, then the agent is a system-specific application. For example, if you include a Sybase database in an Oracle distributed system, then you need to obtain a Sybase-specific transparent gateway so that the Oracle databases in the system can communicate with it.Alternatively, you can use generic connectivity to access nonOracle data stores so long as the non-Oracle system supports the ODBC or OLE DB protocols.  Sites may run different DBMS products, with possibly different underlying data models.  Occurs when sites have implemented their own databases and integration is considered later.  Translations required to allow for:  Different hardware.  Different DBMS products.  Different hardware and different DBMS products.  Typical solution is to use gateways .Database Integration • Goal: providing a uniform access to multiple heterogeneous information sources • More than data exchange (e.g., ASCII, EDI, XML) • Old problem, difficult, well-known (partial)Solutions Concider Scenario Of a Movie Data Base 3 Database System 271
  4. 4. Heterogeneous Database System Presentation Report Data Integration • We did not directly work on it in the project; however, used different service interfaces which requires data interchange • Typically requires (some) manual Interaction Diagrammatic View of HDBMS 4 Database System 271
  5. 5. Heterogeneous Database System Presentation Report 5 Database System 271
  6. 6. Heterogeneous Database System Presentation Report • Manually merge multiple databases into a new global database • Time consuming and error prone • Local autonomy lost • Static solution • Does not scale with number of databases Old-School Approach Multidatabase Language Approach • No attempt at integrating schemas • Language (e.g., SQL) used to integrate information sources at run-time • Not transparent (you need to know all data bases!) • Heavy burden on (expert) users • Global queries subject to local changes 6 Database System 271
  7. 7. Heterogeneous Database System Presentation Report Example Use S1, S2 Select Titre From S1.Book, S2.Livre Where S1.Book.ISBN = S2.Livre.ISBN How to Deal with Autonomy? • Problems  –changing structure of Web page  –different coverage of Web sites  –availability of services • Solutions –manually adapt to changes –replication, materialization (availability) –contacts, agreements, … standards How to Deal with Heterogeneity? • Problems –Data models –Schemas –Data • Solutions –Mappings, schema integration –Standards 7 Database System 271
  8. 8. Heterogeneous Database System Presentation Report HOW Wrappers Works 8 Database System 271
  9. 9. Heterogeneous Database System Presentation Report 9 Database System 271
  10. 10. Heterogeneous Database System Presentation Report Advantages of HDBS Disadvantages of HDBS  Reflects organizational structure  Cost  Improved share ability and local autonomy  Integrity control more difficult  Improved availability  Lack of experience  Improved reliability  Database design more complex  Complexity of management and control  Improved performance  Economics  Modular growth  Data located near site with greatest demand  Faster data access  Lack of standards  Security  Increased storage requirements  Greater difficulty in managing data environment 10 Database System 271
  11. 11. Heterogeneous Database System Presentation Report  Increased training costs  Faster data processing  Growth facilitation  Improved communications  Reduced operating costs  User-friendly interface  Less danger of single-point failure  Processor independence  Heterogeneous Services  Transparent Gateway Agents  Generic Connectivity Tools and technologies       Unix Linux Ms.sql server 2008 My SQL 5.0 CPN ITSE(integrated translation support environment ) Current work on the Heterogeneous database In a heterogeneous distributed database, different sites may use different schema and software. Difference in schema is a major problem for query processing and transaction processing. Sites may not be aware of each other and may provide only limited facilities for cooperation in 11 Database System 271
  12. 12. Heterogeneous Database System Presentation Report transaction processing. In heterogeneous systems, different nodes may have different hardware & software and data structures at various nodes or locations are also incompatible. Different computers and operating systems, database applications or data models may be used at each of the locations. For example, one location may have the latest relational database management technology, while another location may store data using conventional files or old version of database management system. Similarly, one location may have the Windows NT operating system, while another may have UNIX. Heterogeneous systems are usually used when individual sites use their own hardware and software. On heterogeneous system, translations are required to allow communication between different sites (or DBMS). In this system, the users must be able to make requests in a database language at their local sites. Usually the SQL database language is used for this purpose. If the hardware is different, then the translation is straightforward, in which computer codes and word-length is changed. The heterogeneous system is often not technically or economically feasible. In this system, a user at one location may be able to read but not update the data at another location. Future work The heterogeneous future work is on following things Linux operating system Unix operating system It also playing an important role in improving relational database system It also modifies the performance of DBMS Conclusion This report is all about HDBMS its types Classification , Advantages ,disadvantages, tools and technologies used for DDBS. Database over the web servers are distributed in parts. There are two major categories of distributed database system one is Homogeneous And other one is Heterogeneous databases. There are advantages of Heterogeneous database system and also some disadvantages. Advantages includes Reflects organizational structure, Improved share ability and local, autonomy, Improved availability, Improved reliability, Improved performance, Economics, Modular growth , Data located near site with greatest demand and e.t.c and some of the disadvantages are Cost, Integrity control more difficult, Lack of standards, Lack of experience, Database design more complex , Complexity of management and control, Security. We also 12 Database System 271
  13. 13. Heterogeneous Database System Presentation Report discussed the tools and technologies for developing and maintaining the web based DDBS and their modification and integration according to the need of time. Lesson learnt     Gain knowledge about heterogeneous database system We came to know the tools and technologies of heterogeneous database system Learnet about distributed database system We came to know that how much heterogenous database system is globally important. My experience Before this research we didn’t knew that how is data distributed in segments over the network and how it can be access or we can say how we retrieve data by querying over the internet. We were also don’t know that how is data managed by using different tools and their modifications with time. The advantages and disadvantages were also unknown for us.Throughout our research we came to know that what are Heterogeneous database And heterogeneous database system is. Before this we were not aware of such wonderful information about database management over the web servers. Through the research now we are able to tell what are DDBS and their types which includes Heterogeneous Data Base Systems and Hmogeneous database system. Review of Report Reviewed by: ASIM NAWAZ Review Topic: Heterogeneous Databases By going through the report created by Hanzala Akram and Haq Nawaz on the topic heterogeneous databases I observed that report is made according to the given contents of sir as sir Tehseen guided us.The data is presented relatively according to the contents and similarity is shown in the data about the contents of report.The things which we observed that are lacking in the report are below other wise report is created accordingly to the given context. The data about contents except introduction I feel is less detailed which is required. 13 Database System 271
  14. 14. Heterogeneous Database System Presentation Report The data is not more related to the industrial base I feel some details may the report is lacking. I think data relted to contents should be more detailed that can elaborate the complete meanings of infromation required for the reports contents. The advantages and disadvantages are given in tabular form in keypoints but not detailed one. In the section tootls and technologies just the tools names are given but complete detail is not provided. In the section future work there too just some tools are mentioned complete detail also missing . References http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=334882&url=http%3A%2F%2Fieeexplor e.ieee.org%2Fxpls%2Fabs_all.jsp%3Farnumber%3D334882 https://www.google.com.pk/search?q=introduction+of+heterogeneous+database&oq=introductio n+of+heterogeneous+database&aqs=chrome..69i57j0l4.21052j0j4&sourceid=chrome&espv=210 &es_sm=93&ie=UTF-8#es_sm=93&espv=210&q=introduction+to+heterogeneous+database http://www.slideshare.net/adorepump/distributed-databases 14 Database System 271
  15. 15. Heterogeneous Database System Presentation Report http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=334882&url=http%3A%2F%2Fieeexplore.ieee.o rg%2Fxpls%2Fabs_all.jsp%3Farnumber%3D334882 http://docs.oracle.com/cd/B10501_01/server.920/a96521/ds_concepts.htm 15 Database System 271