ch16-Practical Database Design and Tuning

ch16-Practical Database Design and Tuning - Copyright 2007...

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Slide 16- 1 Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe
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Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Chapter 16 Practical Database Design and Tuning
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Slide 16- 3 Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Chapter Outline 1. Physical Database Design in Relational Databases 2. An Overview of Database Tuning in Relational Systems
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Slide 16- 4 Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe 1. Physical Database Design in Relational Databases(1) Factors that Influence Physical Database Design: A. Analyzing the database queries and transactions For each query, the following information is needed. The files that will be accessed by the query; The attributes on which any selection conditions for the query are specified; The attributes on which any join conditions or conditions to link multiple tables or objects for the query are specified; The attributes whose values will be retrieved by the query. Note: the attributes listed in items 2 and 3 above are candidates for definition of access structures.
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Slide 16- 5 Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Physical Database Design in Relational Databases(2) Factors that Influence Physical Database Design (contd.): A. Analyzing the database queries and transactions (contd.) For each update transaction or operation, the following information is needed. 1. The files that will be updated; 2. The type of operation on each file (insert, update or delete); 3. The attributes on which selection conditions for a delete or update operation are specified; 4. The attributes whose values will be changed by an update operation. Note: the attributes listed in items 3 above are candidates for definition of access structures. However, the attributes listed in item 4 are candidates for avoiding an access structure.
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Copyright © 2007 Ramez Elmasri and Shamkant B. Navathe Physical Database Design in Relational Databases(3) Factors that Influence Physical Database Design (contd.): B. Analyzing the expected frequency of invocation of queries and transactions The expected frequency information, along with the attribute information collected on each query and transaction, is used to compile a cumulative list of expected frequency of use for all the queries and transactions. It is expressed as the expected frequency of using each attribute in each file as a selection attribute or join attribute, over all the queries and transactions. 80-20 rule
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This note was uploaded on 02/23/2012 for the course CS 348 taught by Professor Staff during the Fall '08 term at Purdue University-West Lafayette.

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ch16-Practical Database Design and Tuning - Copyright 2007...

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