'Hash index' presentation slideshows

L05: Query Processing & Tuning Queries

L05: Query Processing & Tuning Queries. Query Processing -- Principles Tuning Queries. Query Processing & Optimization. Any high-level query (SQL) on a database must be processed, optimized and executed by the DBMS

831 views • 68 slides

Short Read Mapper

Short Read Mapper. Brian S. Lam CS124. Outline. Biological Motivation Computer Science Problem Trivial Solution Hash Index Solution Future Direction. Outline. Biological Motivation Computer Science Problem Trivial Solution Hash Index Solution Future Direction. Biological Motivation.

437 views • 34 slides

Indexing (Cont.)

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Overview of Query Evaluation

Overview of Query Evaluation. R&G Chapter 12 Lecture 13. Administrivia. Exams graded HW2 due in a week No Office Hours Today. Query Optimization and Execution. Relational Operators. Files and Access Methods. Buffer Management. Disk Space Management. DB. Review: Storage.

426 views • 30 slides

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 :

605 views • 28 slides

Implementation of relational operations (based on slides from UC Berkeley)

Implementation of relational operations (based on slides from UC Berkeley). Query Optimization and Execution. SQL Query. Relational Operators. Files and Access Methods. Buffer Management. Disk Space Management. DB. Introduction.

344 views • 27 slides

Evaluation of Relational Operations

415 views • 24 slides

Overlapping Hash Trie ? A Longest Prefix First Search Scheme for IPv4/IPv6 Lookup

370 views • 22 slides

Overview of Query Evaluation

Overview of Query Evaluation. Chapter 12. Objectives. Preliminaries: Core query processing techniques Catalog Access paths to data Index matching Summary of query processing algorithms Selection Projection Join Introduction to query optimization Query plans

378 views • 22 slides

Query Optimization Advanced Databases By M. Akhtar Ali

Query Optimization Advanced Databases By M. Akhtar Ali. Implementation of Selection (summary) Assuming ? R.attr op value (R). No Index is available on attr and R is not sorted on attr Cost = M I/Os, where M is the number of pages in R

288 views • 20 slides

Evaluation of Relational Operations

Evaluation of Relational Operations. Chapter 14, Part B (Joins). Schema for Examples. Sailors ( sid : integer , sname : string, rating : integer, age : real) Reserves ( sid : integer, bid : integer, day : dates , rname : string). Similar to old schema; rname added for variations.

233 views • 17 slides

Evaluation of Relational Operations

Evaluation of Relational Operations. Chapter 14 (3 rd Edition) , Part A (Joins). Relational Operations. We will consider how to implement: Selection ( ) Selects a subset of rows from relation. Projection ( ) Deletes unwanted columns from relation.

269 views • 16 slides

ICS 321 Fall 2009 Overview of Query Evaluation

ICS 321 Fall 2009 Overview of Query Evaluation. Asst. Prof. Lipyeow Lim Information & Computer Science Department University of Hawaii at Manoa. SELECT * FROM Reserves WHERE sid =101. Query. ? Sid=101. Parse Query. A. B. Reserves. Enumerate Plans. fetch. SCAN ( sid =101).

271 views • 16 slides

Relational Operator Evaluation

Relational Operator Evaluation. Overview. Application Programmer (e.g., business analyst, Data architect). Application. Sophisticated Application Programmer (e.g., SAP admin). Query Processor. Indexes. Storage Subsystem. Concurrency Control. Recovery. DBA, Tuner. Operating System.

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260 views • 14 slides

CIT 383: Administrative Scripting

Hashes. CIT 383: Administrative Scripting. Topics. What is a Hash? Creating Hashes Hash Keys Accessing Hashes Hash Methods Iterators Hashes and Ordering Multi-valued hashes What are hashes good for?. 192.122.237.230. 192.122.237.7. 64.233.167.99. kosh.nku.edu. www.nku.edu.

258 views • 13 slides

Query Optimization Advanced Databases By Dr. Akhtar Ali

Query Optimization Advanced Databases By Dr. Akhtar Ali. Overview of Query Optimization. Logical Optimization: Using some transformation rules and algebraic equivalences To choose different join orders R ? S ? S ? R (Commutative) (R ? S) ? T ? R ? ( S ? T) (Associative)

238 views • 10 slides

Evaluation of Relational Operations

Evaluation of Relational Operations. Chapter 12, Part A. Relational Operations. We will consider how to implement: Selection ( ) Selects a subset of rows from relation. Projection ( ) Deletes unwanted columns from relation.

187 views • 9 slides

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.

232 views • 4 slides

Study Group exercises (3/19 and 3/20)

Study Group exercises (3/19 and 3/20) 1. Consider the Book DB table, assertion, and sample query definitions accompanying this handout. Read through the slide deck ViewsWithBlankShipperView.pptx . On page 5, define a view that is required by a person (or process)

120 views • 1 slides