• Study Resource
  • Explore
    • Arts & Humanities
    • Business
    • Engineering & Technology
    • Foreign Language
    • History
    • Math
    • Science
    • Social Science

    Top subcategories

    • Advanced Math
    • Algebra
    • Basic Math
    • Calculus
    • Geometry
    • Linear Algebra
    • Pre-Algebra
    • Pre-Calculus
    • Statistics And Probability
    • Trigonometry
    • other →

    Top subcategories

    • Astronomy
    • Astrophysics
    • Biology
    • Chemistry
    • Earth Science
    • Environmental Science
    • Health Science
    • Physics
    • other →

    Top subcategories

    • Anthropology
    • Law
    • Political Science
    • Psychology
    • Sociology
    • other →

    Top subcategories

    • Accounting
    • Economics
    • Finance
    • Management
    • other →

    Top subcategories

    • Aerospace Engineering
    • Bioengineering
    • Chemical Engineering
    • Civil Engineering
    • Computer Science
    • Electrical Engineering
    • Industrial Engineering
    • Mechanical Engineering
    • Web Design
    • other →

    Top subcategories

    • Architecture
    • Communications
    • English
    • Gender Studies
    • Music
    • Performing Arts
    • Philosophy
    • Religious Studies
    • Writing
    • other →

    Top subcategories

    • Ancient History
    • European History
    • US History
    • World History
    • other →

    Top subcategories

    • Croatian
    • Czech
    • Finnish
    • Greek
    • Hindi
    • Japanese
    • Korean
    • Persian
    • Swedish
    • Turkish
    • other →
 
Profile Documents Logout
Upload
syllabus - Sharada Vikas Trust
syllabus - Sharada Vikas Trust

... The Entity-Relationship Data Model, Introduction of entity Relationship model, Elements of the E/R Model, Requirement, Relationship, Entity-Relationship Diagrams, Multiplicity of Binary E/R Relationships, Design Principles, Avoiding Redundancy, Simplicity Counts, Extended ER Models ...
SE487 outline - current Term
SE487 outline - current Term

... office :W344 ...
slides - CIS @ Temple University
slides - CIS @ Temple University

...  Multiple transactions are allowed to run concurrently in the system. ...
Transaction Management Overview
Transaction Management Overview

... If a transaction Ti is aborted, all its actions have to be undone. Not only that, if Tj reads an object last written by Ti, Tj must be aborted as well! Most systems avoid such cascading aborts by releasing a transaction’s locks only at commit time. ...
transaction
transaction

... • Can lead to the undoing of a significant amount of work ...
Transaction Management Overview
Transaction Management Overview

... If a transaction Ti is aborted, all its actions have to be undone. Not only that, if Tj reads an object last written by Ti, Tj must be aborted as well!  Most systems avoid such cascading aborts by releasing a transaction’s locks only at commit time. ...
Calvin: Fast Distributed Transactions for Partitioned Database Systems
Calvin: Fast Distributed Transactions for Partitioned Database Systems

... Transactions Input •Replication group – All replicas of a particular partition •All the requests are forwarded to the master replica • Sequencer component forwards batch to slave replicas in its replication ...
Regis University Graduate Program  MSCD 600 Database Architecture Name: ________________________
Regis University Graduate Program MSCD 600 Database Architecture Name: ________________________

... a. A database system that manages a very large database b. A database system that provides access to many concurrent users c. A database system that must guarantee constant availability d. A database system that is shut down every night for a backup ...
6. Database Management Systems
6. Database Management Systems

... • File Organization , Organization of records in files , Data dictionary storage • Basic Indexing Concepts, rdered Indices, B+ Trees and B tree Index Files • Static hashing, Dynamic hashing • Index Definition in SQL, multiple key access Transaction : • Transaction Concepts, Transaction states • Impl ...
012051054A
012051054A

... locking protocol requires that in addition to locking being two-phase, all exclusive-mode locks taken by a transaction must be held until that transaction commits. The strict two-phase locking (S2PL) class of schedules is the intersection of the 2PL class with the class of schedules possessing the S ...
CSC 443 – Database Management Systems Databases
CSC 443 – Database Management Systems Databases

... Isolation • Deals with the execution of multiple transactions concurrently. • If the initial database state is consistent and accurately reflects the real-world state, then the serial (one after another) execution of a set of consistent transactions preserves consistency. • But serial execution is ...
Recovery in Parallel Database Systems
Recovery in Parallel Database Systems

... Once a transaction completes successfully(commits), its changes to the state survive failures. ...
Lecture10-Transactio..
Lecture10-Transactio..

... • Phase 2: A transaction releases locks at the end – when it aborts or commits • Non-strict two-phase locking allows releasing locks before the end of the transaction, but after the transaction acquired all the locks it needed • Non-strict two-phase locking is often impractical, because: – We do not ...
Forward-Engineering ERD and Data Using MySQL Workbench
Forward-Engineering ERD and Data Using MySQL Workbench

... a. “Catalog Tree” in left-pane b. Rt-click database > Edit Schema > rename database to your username ...
Document
Document

...  The DBMS will lock an entire disk-page. A disk-page or page is the equivalent of a disk-block, which may be described as a (referenced) section of a disk. A page has a fixed size, such as 4K, 8K, 16K, etc. A table may span several pages, and a page may contain several rows of one or more tables. P ...
Distributed Databases - Computer Information Systems
Distributed Databases - Computer Information Systems

... master table is copied to one or more remote databases. Changes in the master table are reflected in the snapshot tables whenever snapshot refreshes, as determined by the snapshot site. ...
slides
slides

... to enhance the previous knowledge of database systems by deepening the understanding of the theoretical and practical aspects of the database technologies; to show the need for distributed database technology to tackle deficiencies of centralized database systems; to introduce basic principles and i ...
No Slide Title - American University
No Slide Title - American University

... • Serializability means that a series of concurrent transactions will yield the same result as if they were executed one after another. • Isolation means that the data required by an executing transaction cannot be accessed by any other transaction until the first transaction finishes. This property ...
Distributed DBMS Security
Distributed DBMS Security

... Security issues in Distributed Databases are more complex as compared to Centralized Databases. But they can be taken care of through careful study. ...
4. Transaction processing concepts
4. Transaction processing concepts

... Forms of serializability Corresponding to the forms of equivalence: • Conflict serializability: Simple testing algorithm • View serializability: Less restrictive than conflict serializability. Testing is an NP-complete problem. Note. Every conflict-serializable schedule is also view-serializable, b ...
Lecture 5
Lecture 5

... Preventing Inconsistent Analysis Problem using 2PL ...
Lecture 28
Lecture 28

... • A schedule is conflict serializable if and only if its precedence graph is acyclic. • Cycle-detection algorithms exist which take order n2 time, where n is the number of vertices in the graph. – (Better algorithms take order n + e where e is the number of edges.) • If precedence graph is acyclic, ...
Databases at Risk - ESG - Enterprise Strategy Group
Databases at Risk - ESG - Enterprise Strategy Group

... ...
DataBridge SS Data Sheet
DataBridge SS Data Sheet

... • Store all your weighing records in an optimized and secure database • Information is at your fingertips, making it easy to retrieve • Eliminate stacks of paperwork that can get lost or out of order • Compile reports with a single click and export transactions for ...
91.309/310 Database
91.309/310 Database

... • A database is a very large, integrated collection of data. • A database management system (DBMS) is a software package designed to store and manage data efficiently, e.g., MS Access, MySQL, IBM DB2, Oracle, MS SQL Server. ...
< 1 ... 57 58 59 60 61 62 63 >

Commitment ordering

Commitment ordering (CO) is a class of interoperable serializability techniques in concurrency control of databases, transaction processing, and related applications. It allows optimistic (non-blocking) implementations. With the proliferation of multi-core processors, CO has been also increasingly utilized in concurrent programming, transactional memory, and especially in software transactional memory (STM) for achieving serializability optimistically. CO is also the name of the resulting transaction schedule (history) property, which was originally defined in 1988 with the name dynamic atomicity. In a CO compliant schedule the chronological order of commitment events of transactions is compatible with the precedence order of the respective transactions. CO is a broad special case of conflict serializability, and effective means (reliable, high-performance, distributed, and scalable) to achieve global serializability (modular serializability) across any collection of database systems that possibly use different concurrency control mechanisms (CO also makes each system serializability compliant, if not already).Each not-CO-compliant database system is augmented with a CO component (the commitment order coordinator—COCO) which orders the commitment events for CO compliance, with neither data-access nor any other transaction operation interference. As such CO provides a low overhead, general solution for global serializability (and distributed serializability), instrumental for global concurrency control (and distributed concurrency control) of multi database systems and other transactional objects, possibly highly distributed (e.g., within cloud computing, grid computing, and networks of smartphones). An atomic commitment protocol (ACP; of any type) is a fundamental part of the solution, utilized to break global cycles in the conflict (precedence, serializability) graph. CO is the most general property (a necessary condition) that guarantees global serializability, if the database systems involved do not share concurrency control information beyond atomic commitment protocol (unmodified) messages, and have no knowledge whether transactions are global or local (the database systems are autonomous). Thus CO (with its variants) is the only general technique that does not require the typically costly distribution of local concurrency control information (e.g., local precedence relations, locks, timestamps, or tickets). It generalizes the popular strong strict two-phase locking (SS2PL) property, which in conjunction with the two-phase commit protocol (2PC) is the de facto standard to achieve global serializability across (SS2PL based) database systems. As a result CO compliant database systems (with any, different concurrency control types) can transparently join such SS2PL based solutions for global serializability.In addition, locking based global deadlocks are resolved automatically in a CO based multi-database environment, an important side-benefit (including the special case of a completely SS2PL based environment; a previously unnoticed fact for SS2PL).Furthermore, strict commitment ordering (SCO; Raz 1991c), the intersection of Strictness and CO, provides better performance (shorter average transaction completion time and resulting better transaction throughput) than SS2PL whenever read-write conflicts are present (identical blocking behavior for write-read and write-write conflicts; comparable locking overhead). The advantage of SCO is especially significant during lock contention. Strictness allows both SS2PL and SCO to use the same effective database recovery mechanisms.Two major generalizing variants of CO exist, extended CO (ECO; Raz 1993a) and multi-version CO (MVCO; Raz 1993b). They as well provide global serializability without local concurrency control information distribution, can be combined with any relevant concurrency control, and allow optimistic (non-blocking) implementations. Both use additional information for relaxing CO constraints and achieving better concurrency and performance. Vote ordering (VO or Generalized CO (GCO); Raz 2009) is a container schedule set (property) and technique for CO and all its variants. Local VO is a necessary condition for guaranteeing global serializability, if the atomic commitment protocol (ACP) participants do not share concurrency control information (have the generalized autonomy property). CO and its variants inter-operate transparently, guaranteeing global serializability and automatic global deadlock resolution also together in a mixed, heterogeneous environment with different variants.
  • studyres.com © 2025
  • DMCA
  • Privacy
  • Terms
  • Report