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Database Systems - Introduction

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Definitions in database systems, problems with record files, database management system architecture.

Definitions in database systems, problems with record files, database management system architecture.

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  • 1. Problem De
  • 2. nition Database Management Systems References Database Systems Introduction H. Turgut Uyar Sule Oguducu 2002-2014 H. Turgut Uyar, Sule Oguducu Database Systems
  • 3. Problem De
  • 4. nition Database Management Systems References License c 2002-2014 T. Uyar, S. Oguducu You are free to: Share { copy and redistribute the material in any medium or format Adapt { remix, transform, and build upon the material Under the following terms: Attribution { You must give appropriate credit, provide a link to the license, and indicate if changes were made. NonCommercial { You may not use the material for commercial purposes. ShareAlike { If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original. For more information: https://creativecommons.org/licenses/by-nc-sa/4.0/ Read the full license: https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode H. Turgut Uyar, Sule Oguducu Database Systems
  • 5. Problem De
  • 6. nition Database Management Systems References Topics 1 Problem De
  • 7. nition Introduction Problems 2 Database Management Systems Introduction Client / Server SQL H. Turgut Uyar, Sule Oguducu Database Systems
  • 8. Problem De
  • 9. nition Database Management Systems References Introduction Problems Topics 1 Problem De
  • 10. nition Introduction Problems 2 Database Management Systems Introduction Client / Server SQL H. Turgut Uyar, Sule Oguducu Database Systems
  • 11. Problem De
  • 12. nition Database Management Systems References Introduction Problems Problem De
  • 13. nition aim: store and process large amounts of data eectively basic operations: add new data change existing data delete data query data: planned - ad hoc CRUD: create - read - update - delete H. Turgut Uyar, Sule Oguducu Database Systems
  • 14. Problem De
  • 15. nition Database Management Systems References Introduction Problems Problem De
  • 16. nition aim: store and process large amounts of data eectively basic operations: add new data change existing data delete data query data: planned - ad hoc CRUD: create - read - update - delete H. Turgut Uyar, Sule Oguducu Database Systems
  • 17. Problem De
  • 18. nition Database Management Systems References Introduction Problems Data persistent data: data that must be stored due to the nature of the information temporary data output data: data that can be derived from persistent data (query results, reports, etc.) input data: unprocessed data that just entered the system can be added to persistent data can cause changes in persistent data can be ignored completely H. Turgut Uyar, Sule Oguducu Database Systems
  • 19. Problem De
  • 20. nition Database Management Systems References Introduction Problems Data persistent data: data that must be stored due to the nature of the information temporary data output data: data that can be derived from persistent data (query results, reports, etc.) input data: unprocessed data that just entered the system can be added to persistent data can cause changes in persistent data can be ignored completely H. Turgut Uyar, Sule Oguducu Database Systems
  • 21. Problem De
  • 22. nition Database Management Systems References Introduction Problems Roles end users: people who work on the data assumed not to have any technical knowledge application programmers: people who develop the programs that the end users use H. Turgut Uyar, Sule Oguducu Database Systems
  • 23. Problem De
  • 24. nition Database Management Systems References Introduction Problems Roles end users: people who work on the data assumed not to have any technical knowledge application programmers: people who develop the programs that the end users use H. Turgut Uyar, Sule Oguducu Database Systems
  • 25. Problem De
  • 26. nition Database Management Systems References Introduction Problems Application Example Example (university student data) Student Aairs: student name, number, department, courses taken, internships, etc. common data: student name, number, department, etc. Library: student name, number, department, books lent, etc. application speci
  • 27. c data: courses, internships, books, etc. H. Turgut Uyar, Sule Oguducu Database Systems
  • 28. Problem De
  • 29. nition Database Management Systems References Introduction Problems Application Example Example (university student data) Student Aairs: student name, number, department, courses taken, internships, etc. common data: student name, number, department, etc. Library: student name, number, department, books lent, etc. application speci
  • 30. c data: courses, internships, books, etc. H. Turgut Uyar, Sule Oguducu Database Systems
  • 31. Problem De
  • 32. nition Database Management Systems References Introduction Problems Record Files every application has its own data every application keeps its data in the
  • 33. les that it manages itself H. Turgut Uyar, Sule Oguducu Database Systems
  • 34. Problem De
  • 35. nition Database Management Systems References Introduction Problems Topics 1 Problem De
  • 36. nition Introduction Problems 2 Database Management Systems Introduction Client / Server SQL H. Turgut Uyar, Sule Oguducu Database Systems
  • 37. Problem De
  • 38. nition Database Management Systems References Introduction Problems Redundancy the same data is kept in multiple places waste of disk space Example the names, numbers and departments of students are kept both in Student Aairs and in the Library H. Turgut Uyar, Sule Oguducu Database Systems
  • 39. Problem De
  • 40. nition Database Management Systems References Introduction Problems Redundancy the same data is kept in multiple places waste of disk space Example the names, numbers and departments of students are kept both in Student Aairs and in the Library H. Turgut Uyar, Sule Oguducu Database Systems
  • 41. Problem De
  • 42. nition Database Management Systems References Introduction Problems Inconsistency multiple copies of the same data can become dierent Example the name of the same student can be recorded as Victoria Adams in Student Aairs and as Victoria Beckhamin the Library H. Turgut Uyar, Sule Oguducu Database Systems
  • 43. Problem De
  • 44. nition Database Management Systems References Introduction Problems Inconsistency multiple copies of the same data can become dierent Example the name of the same student can be recorded as Victoria Adams in Student Aairs and as Victoria Beckhamin the Library H. Turgut Uyar, Sule Oguducu Database Systems
  • 45. Problem De
  • 46. nition Database Management Systems References Introduction Problems Loss of Integrity it is dicult to keep the data correct Example the Control and Computer Engineering department is closed but the department data of its students remains the same H. Turgut Uyar, Sule Oguducu Database Systems
  • 47. Problem De
  • 48. nition Database Management Systems References Introduction Problems Loss of Integrity it is dicult to keep the data correct Example the Control and Computer Engineering department is closed but the department data of its students remains the same H. Turgut Uyar, Sule Oguducu Database Systems
  • 49. Problem De
  • 50. nition Database Management Systems References Introduction Problems Diculties in New Applications a lot of work must be duplicated for every new application Example a new application will be developed for the Scholarship Oce H. Turgut Uyar, Sule Oguducu Database Systems
  • 51. Problem De
  • 52. nition Database Management Systems References Introduction Problems Diculties in New Applications a lot of work must be duplicated for every new application Example a new application will be developed for the Scholarship Oce H. Turgut Uyar, Sule Oguducu Database Systems
  • 53. Problem De
  • 54. nition Database Management Systems References Introduction Problems Policy Gaps no standards in the applications of the institution dierent paradigms, methods, programming languages data transfer between applications each department considers only its own requirements H. Turgut Uyar, Sule Oguducu Database Systems
  • 55. Problem De
  • 56. nition Database Management Systems References Introduction Problems Policy Gaps no standards in the applications of the institution dierent paradigms, methods, programming languages data transfer between applications each department considers only its own requirements H. Turgut Uyar, Sule Oguducu Database Systems
  • 57. Problem De
  • 58. nition Database Management Systems References Introduction Problems Security hard to de
  • 59. ne detailed security permissions security depends only on the operating system H. Turgut Uyar, Sule Oguducu Database Systems
  • 60. Problem De
  • 61. nition Database Management Systems References Introduction Problems Data Dependence De
  • 62. nition data dependence: application code depends on the organization of the data and the access method hard to make changes in the code H. Turgut Uyar, Sule Oguducu Database Systems
  • 63. Problem De
  • 64. nition Database Management Systems References Introduction Problems Data Dependence Example the student number is a string in Student Aairs but a number in the Library the Student Aairs application keeps a B-tree index on the student number B-tree search algorithms are used in queries H. Turgut Uyar, Sule Oguducu Database Systems
  • 65. Problem De
  • 66. nition Database Management Systems References Introduction Problems Data Dependence Example the student number is a string in Student Aairs but a number in the Library the Student Aairs application keeps a B-tree index on the student number B-tree search algorithms are used in queries H. Turgut Uyar, Sule Oguducu Database Systems
  • 67. Problem De
  • 68. nition Database Management Systems References Introduction Client / Server SQL Topics 1 Problem De
  • 69. nition Introduction Problems 2 Database Management Systems Introduction Client / Server SQL H. Turgut Uyar, Sule Oguducu Database Systems
  • 70. Problem De
  • 71. nition Database Management Systems References Introduction Client / Server SQL Database Management Systems data is kept in a shared system applications access data over a common interface H. Turgut Uyar, Sule Oguducu Database Systems
  • 72. Problem De
  • 73. nition Database Management Systems References Introduction Client / Server SQL ANSI/SPARC Architecture H. Turgut Uyar, Sule Oguducu Database Systems
  • 74. Problem De
  • 75. nition Database Management Systems References Introduction Client / Server SQL External Level external level from the end user's perspective: the data needed by that end user the interface of the application that she is using external level from the application programmer's perspective: the programming language she uses the extensions to this language for database operations: data sublanguage H. Turgut Uyar, Sule Oguducu Database Systems
  • 76. Problem De
  • 77. nition Database Management Systems References Introduction Client / Server SQL External Level external level from the end user's perspective: the data needed by that end user the interface of the application that she is using external level from the application programmer's perspective: the programming language she uses the extensions to this language for database operations: data sublanguage H. Turgut Uyar, Sule Oguducu Database Systems
  • 78. Problem De
  • 79. nition Database Management Systems References Introduction Client / Server SQL Conceptual Level conceptual level: the entire data where data independence is achieved catalogue: de
  • 80. nitions that describe the content of the data databases data types, integrity constraints users, privileges, security constraints H. Turgut Uyar, Sule Oguducu Database Systems
  • 81. Problem De
  • 82. nition Database Management Systems References Introduction Client / Server SQL Conceptual Level conceptual level: the entire data where data independence is achieved catalogue: de
  • 83. nitions that describe the content of the data databases data types, integrity constraints users, privileges, security constraints H. Turgut Uyar, Sule Oguducu Database Systems
  • 84. Problem De
  • 85. nition Database Management Systems References Introduction Client / Server SQL Internal Level internal level: implementation details how the data is represented
  • 86. les, records how the data is accessed pointers, indexes, B-trees H. Turgut Uyar, Sule Oguducu Database Systems
  • 87. Problem De
  • 88. nition Database Management Systems References Introduction Client / Server SQL Internal Level internal level: implementation details how the data is represented
  • 89. les, records how the data is accessed pointers, indexes, B-trees H. Turgut Uyar, Sule Oguducu Database Systems
  • 90. Problem De
  • 91. nition Database Management Systems References Introduction Client / Server SQL Conversions conversions between levels for data independence Example (conceptual - external) present the student number as a string to the Student Aairs application, and as a number to the Library application Example (conceptual - internal) generate an index on the student number H. Turgut Uyar, Sule Oguducu Database Systems
  • 92. Problem De
  • 93. nition Database Management Systems References Introduction Client / Server SQL Conversions conversions between levels for data independence Example (conceptual - external) present the student number as a string to the Student Aairs application, and as a number to the Library application Example (conceptual - internal) generate an index on the student number H. Turgut Uyar, Sule Oguducu Database Systems
  • 94. Problem De
  • 95. nition Database Management Systems References Introduction Client / Server SQL Conversions conversions between levels for data independence Example (conceptual - external) present the student number as a string to the Student Aairs application, and as a number to the Library application Example (conceptual - internal) generate an index on the student number H. Turgut Uyar, Sule Oguducu Database Systems
  • 96. Problem De
  • 97. nition Database Management Systems References Introduction Client / Server SQL Administrator Roles data administator: makes the decisions which data will be stored? who can access which data? database administrator: applies the decisions de
  • 98. nes the conceptual - external/internal conversions adjusts system performance guarantees system availability H. Turgut Uyar, Sule Oguducu Database Systems
  • 99. Problem De
  • 100. nition Database Management Systems References Introduction Client / Server SQL Administrator Roles data administator: makes the decisions which data will be stored? who can access which data? database administrator: applies the decisions de
  • 101. nes the conceptual - external/internal conversions adjusts system performance guarantees system availability H. Turgut Uyar, Sule Oguducu Database Systems
  • 102. Problem De
  • 103. nition Database Management Systems References Introduction Client / Server SQL DBMS Functions data de
  • 104. nition language data manipulation language checking whether data manipulation requests conform to integrity and security constraints processing simultaneous requests properly performance H. Turgut Uyar, Sule Oguducu Database Systems
  • 105. Problem De
  • 106. nition Database Management Systems References Introduction Client / Server SQL DBMS Functions data de
  • 107. nition language data manipulation language checking whether data manipulation requests conform to integrity and security constraints processing simultaneous requests properly performance H. Turgut Uyar, Sule Oguducu Database Systems
  • 108. Problem De
  • 109. nition Database Management Systems References Introduction Client / Server SQL DBMS Functions data de
  • 110. nition language data manipulation language checking whether data manipulation requests conform to integrity and security constraints processing simultaneous requests properly performance H. Turgut Uyar, Sule Oguducu Database Systems
  • 111. Problem De
  • 112. nition Database Management Systems References Introduction Client / Server SQL DBMS Functions data de
  • 113. nition language data manipulation language checking whether data manipulation requests conform to integrity and security constraints processing simultaneous requests properly performance H. Turgut Uyar, Sule Oguducu Database Systems
  • 114. Problem De
  • 115. nition Database Management Systems References Introduction Client / Server SQL DBMS Functions data de
  • 116. nition language data manipulation language checking whether data manipulation requests conform to integrity and security constraints processing simultaneous requests properly performance H. Turgut Uyar, Sule Oguducu Database Systems
  • 117. Problem De
  • 118. nition Database Management Systems References Introduction Client / Server SQL Topics 1 Problem De
  • 119. nition Introduction Problems 2 Database Management Systems Introduction Client / Server SQL H. Turgut Uyar, Sule Oguducu Database Systems
  • 120. Problem De
  • 121. nition Database Management Systems References Introduction Client / Server SQL Client / Server Architecture server: provides the DBMS functions client: provides the interaction between the user and the server vendor supplied tools (query processors, report generators, etc.) applications developed by application programmers H. Turgut Uyar, Sule Oguducu Database Systems
  • 122. Problem De
  • 123. nition Database Management Systems References Introduction Client / Server SQL Client / Server Architecture server: provides the DBMS functions client: provides the interaction between the user and the server vendor supplied tools (query processors, report generators, etc.) applications developed by application programmers H. Turgut Uyar, Sule Oguducu Database Systems
  • 124. Problem De
  • 125. nition Database Management Systems References Introduction Client / Server SQL Architecture the client and the server can be on the same computer or on dierent computers H. Turgut Uyar, Sule Oguducu Database Systems
  • 126. Problem De
  • 127. nition Database Management Systems References Introduction Client / Server SQL Multiple Clients / Single Server many clients can connect to a single server server is a bottleneck replication H. Turgut Uyar, Sule Oguducu Database Systems
  • 128. Problem De
  • 129. nition Database Management Systems References Introduction Client / Server SQL Multiple Clients / Single Server many clients can connect to a single server server is a bottleneck replication H. Turgut Uyar, Sule Oguducu Database Systems
  • 130. Problem De
  • 131. nition Database Management Systems References Introduction Client / Server SQL Topics 1 Problem De
  • 132. nition Introduction Problems 2 Database Management Systems Introduction Client / Server SQL H. Turgut Uyar, Sule Oguducu Database Systems
  • 133. Problem De
  • 134. nition Database Management Systems References Introduction Client / Server SQL SQL Structured Query Language data de
  • 135. nition language data manipulation language interaction with general purpose programming languages history started by IBM in the 1970s standards: 1992, 1999, 2003 H. Turgut Uyar, Sule Oguducu Database Systems
  • 136. Problem De
  • 137. nition Database Management Systems References Introduction Client / Server SQL SQL Structured Query Language data de
  • 138. nition language data manipulation language interaction with general purpose programming languages history started by IBM in the 1970s standards: 1992, 1999, 2003 H. Turgut Uyar, Sule Oguducu Database Systems
  • 139. Problem De
  • 140. nition Database Management Systems References Introduction Client / Server SQL SQL Products Oracle IBM DB2, Progress, MS-SQL, Sybase open source: PostgreSQL, MySQL, Firebird embedded: SQLite, MS Access H. Turgut Uyar, Sule Oguducu Database Systems
  • 141. Problem De
  • 142. nition Database Management Systems References References Required Reading: Date Chapter 1: An Overview of Database Management 1.4. Why Database? 1.5. Data Independence Chapter 2: Database System Architecture H. Turgut Uyar, Sule Oguducu Database Systems

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