'Clustered index' diaporamas de présentation

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CS 540 Database Management Systems

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File Organizations and Indexing Chapter 8

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Module 6: Planning Indexes

Module 6: Planning Indexes. Overview. Introduction to Indexes Index Architecture How SQL Server Retrieves Stored Data How SQL Server Maintains Index and Heap Structures Deciding Which Columns to Index. Introduction to Indexes. How SQL Server Stores and Accesses Data

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Module 5: Planning Indexes

Module 5: Planning Indexes. Overview. Introducing Indexes Understanding Index Architecture Retrieving Stored Data with SQL Server Maintaining Index and Heap Structures in SQL Server Deciding Which Columns to Index. Lesson: Introducing Indexes. How SQL Server Stores and Accesses Data

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Module 6: Creating and Maintaining Indexes

Module 6: Creating and Maintaining Indexes. Overview. Creating Indexes Understanding Index Creation Options Maintaining Indexes Introducing Statistics Using the Index Tuning Wizard. Lesson: Creating Indexes. Guidelines for Creating and Dropping Indexes

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Overview of Query Evaluation

Overview of Query Evaluation. Chapter 12. Outline. Query Optimization Overview Algorithm for Relational Operations. Overview of Query Evaluation. DBMS keeps descriptive data in system catalogs. SQL queries are translated into an extended form of relational algebra: Query Plan Reasoning :

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Objectives In this lesson, you will learn to: Create a clustered index Create a nonclustered index

Objectives In this lesson, you will learn to: Create a clustered index Create a nonclustered index Use the Index Tuning Wizard Understand Index Enhancements. Getting Started

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Module 8 Improving Performance through Nonclustered Indexes

Module 8 Improving Performance through Nonclustered Indexes. Module Overview. Designing Effective Nonclustered Indexes Implementing Nonclustered Indexes Using the Database Engine Tuning Advisor. Lesson 1: Designing Effective Nonclustered Indexes. What is a Nonclustered Index?

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Lecture 25: Query Optimization

Lecture 25: Query Optimization. Wednesday, November 22, 2000. Outline. Finish index-based algorithms From SQL to logical plans (7.3) Algebraic laws (7.2). Index Based Selection. Selection on equality: s a=v (R) Clustered index on a: cost B(R)/V(R,a)

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????? ??? ???? B-Tree ?? ? Page ?? ? Extent ?? ????? Page Split ? ??????? ?? ?? ????? ? ??????? ? ????? ????? ?????? ?? ?????? ??? XML ??????? ? ?? ??? ????? Index ??. ?????? ??. NON-CLUSTERED INDEX On a Heap. NON-CLUSTERED INDEX On a CLUSTERED INDEX.

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SQL Server 2005 features for VLDBs

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Overview of Storage and Indexing

Overview of Storage and Indexing. Data on External Storage. Disks: Can retrieve random page at fixed cost But reading several consecutive pages is much cheaper than reading them in random order Tapes: Can only read pages in sequence Cheaper than disks; used for archival storage

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Indexing Internals

Indexing Internals. Denny Cherry mrdenny@mrdenny.com twitter.com/ mrdenny. About Me. Author or Coauthor of 4 books 8+ SQL Mag articles Dozens of other articles Microsoft MVP since Oct 2008 Microsoft Certified Master Founder of SQL Excursions Independent Consultant.

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Employees

Notes on: Clusters Index and Cluster Creation in SQL Elisa Bertino CS Department and CERIAS Purdue University. Employees. Departments. Clustering. Consider the following query: SELECT Emp#, Name, Office FROM Employees, Departments WHERE Employees.Dept# = Departments. Dept#

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T-SQL: Simple Changes That Go a Long Way

T-SQL: Simple Changes That Go a Long Way. DAVE VALENTINE @ ingeniousSQL ingeniousSQL.com linkedin.com/in/ ingenioussql. Agenda. Functionality OUTPUT Table Valued Parameter Window Functions Common Table Expressions. Performance Heaps CLUSTERED INDEX NONCLUSTERED INDEX SARGable.

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Lecture 23: Query Execution

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Relational Query Optimization

Relational Query Optimization. Module 5, Lecture 2. Overview of Query Optimization. Plan : Tree of R.A. ops, with choice of alg for each op.

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How SQL Server Stores and Accesses Data

Con. Rudd. Akhtar. Smith. Martin. Ganio. Funk. White. Funk. Ota. Phua. Jones. White. Barr. Smith. Jones. Jones. Hall. Martin. Smith. How SQL Server Stores and Accesses Data. How Data Is Stored Rows are stored in data pages Heaps are a collection of data pages for a table

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Costs

Costs. Btree levels. Typical order: 100. Typical fill-factor: 67%. average fanout = 133 Typical capacities: Level 1 = 133 keys Level 2 = 133 2 ( 17689 ) keys Level 3 = 133 3 ( 2,352,637 ) keys Level 4 = 133 4 ( 312,900,700 ) keys. Costs for single relation plans on R.

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