PPT-CHAPTER 21 Concurrency Control Techniques

Introduction Concurrency control protocols Set of rules to guarantee serializability Twophase locking protocols Lock data items to prevent concurrent access Timestamp Unique identifier for each transaction. Slide . 1. Too Much Milk. . Roommate . A. 3:00. Arrive home: no milk. 3:05. Leave for store. 3:10. Arrive at store. 3:15. Leave store. 3:20. Arrive home, put milk away. CS 140 Lecture Notes: Concurrency. 1. Emmett . Witchel. The University of Texas At Austin. Q: When is everything happening?. A: Now. A: Concurrently. 2. Concurrency is central to CS. CS is at forefront of understanding concurrency. We operate near light speed. Seminar: Transaction Processing (Bachelor). SS 2009. Dennis . Stratmann. Outline. Goal and Overview. Examine Three Approaches to CC on RD:. 1. Predicate-Oriented Concurrency Control. 2. Relational Update Transactions. What is it?. What is concurrency?. Concurrency is not a new idea…. Concurrency was first developed by the ancient Babylonians.. They thought about stuff, walked, and chewed gum … all at the same time.. concurrency. . controll. Chapter. 13. “Distributed Systems: . Concepts and Design”. Coulouris. , . Dollimore. , Kindberg. Hanna. Björling, . Stina Fröjd & Liv Sundman. Transaction. A transaction is a point where there is interaction with the database. Main-Memory Workloads. Iraklis. . Psaroudakis. (EPFL). , Tobias Scheuer (SAP AG), Norman May (SAP AG), Anastasia Ailamaki (EPFL). 1. Scheduling for high concurrency. 2. Queries >> H/W contexts. on Program . Analysis. Weizmann Institute . of Science. Guy Katz. and David . Harel. Overview. Program analysis: verification, repair, synthesis, . etc. Very desirable, but very difficult. State explosion. Architectures, Algorithms and Systems. Chapter Outline. The architecture/system trade-off space. Concurrency improves energy-efficiency. Exploring alternative topologies. Removing inefficiency. The cost of flexibility . Median of a Triangle. A line segment connecting a vertex of a triangle to the midpoint of the opposite side. On a piece of graph paper, graph the triangle with vertices A(2, 1) B(5, 8) C(8, 3). . Find the midpoint of each side and label the midpoint opposite A “D”, opposite B “E”, opposite C “F”. . Lecture 1. Introduction to Multithreading & Fork-Join Parallelism. Steve . Wolfman. , based on work by Dan . Grossman. LICENSE. : This file is licensed under a . Creative . Commons Attribution 3.0 . Database Concurrency Control. 1 Purpose of Concurrency Control. To enforce Isolation (through mutual exclusion) among conflicting transactions. . To preserve database consistency through consistency preserving execution of transactions.. Software & the Concurrency Revolution by Sutter & Larus ACM Queue Magazine, Sept. 2005 For CMPS 5433 - Halverson 1 In a Nutshell “The concurrency revolution is primarily a software revolution -. Bhavya. . Kilari. Dr. . Yanqing. Zhang, . CSc. 8320. PREVIEW. P. ART. I. : . I. NTRODUCTION. Transaction Processing System [. R. Chow & T. Johnson, 1997. Some slides adapted from . Navathe. et. Al. , . Silberchatz. et. Al and . Hector Garcia-Molina . Lock Based Protocols. A lock is a mechanism to control concurrent access to a data item. Data items can be locked in two modes :.