Optimistic Concurrency Control
Optimistic concurrency control (OCC), also known as optimistic locking, is a non-locking concurrency control method applied to transactional systems such as relational database management systems and software transactional memory. OCC assumes that multiple transactions can frequently complete without interfering with each other. While running, transactions use data resources without acquiring locks on those resources. Before committing, each transaction verifies that no other transaction has modified the data it has read. If the check reveals conflicting modifications, the committing transaction rolls back and can be restarted. Optimistic concurrency control was first proposed in 1979 by H. T. Kung and John T. Robinson. OCC is generally used in environments with low data contention. When conflicts are rare, transactions can complete without the expense of managing locks and without having transactions wait for other transactions' locks to clear, leading to higher throughput than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Non-lock Concurrency Control
In Computer Science, in the field of databases, non-lock concurrency control is a concurrency control method used in relational databases without using lock (computer science), locking. There are several non-lock concurrency control methods, which involve the use of timestamps on transaction to determine transaction priority: * Optimistic concurrency control ** Timestamp-based concurrency control ** Validation-based concurrency control ** Multiversion concurrency control *** Snapshot isolation See also * Concurrency pattern * InterBase * Lock-free and wait-free algorithms References Concurrency control Transaction processing {{Database-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Microsoft
Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The early 1980s and home computers, rise of personal computers through software like Windows, and the company has since expanded to Internet services, cloud computing, video gaming and other fields. Microsoft is the List of the largest software companies, largest software maker, one of the Trillion-dollar company, most valuable public U.S. companies, and one of the List of most valuable brands, most valuable brands globally. Microsoft was founded by Bill Gates and Paul Allen to develop and sell BASIC interpreters for the Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Windows. During the 41 years from 1980 to 2021 Microsoft released 9 versions of MS-DOS with a median frequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Firebird (database Server)
Firebird and fire bird may refer to: Mythical birds * Phoenix (mythology), sacred firebird found in the mythologies of many cultures ** Fenghuang, sometimes called Chinese phoenix * Vermilion bird, one of the four symbols of the Chinese constellation representing fire * Bennu, Egyptian firebird * Huma bird, Persian firebird * Firebird (Slavic folklore) Automobiles * Pontiac Firebird, American pony car * General Motors Firebird, series of concept cars Aviation * AAM-A-1 Firebird, an American air-to-air missile of the 1940s * Chengdu J-10 (NATO reporting name: Firebird), a Chinese combat aircraft * Northrop Grumman Firebird, an American recon/surveillance aircraft * CargoLogicAir, a defunct British airline (callsign: FIREBIRD) Film and television * ''Firebird'' (film), a 2021 film directed by Peeter Rebane * ''The Firebird'' (1934 film), a murder mystery directed by William Dieterle * ''The Firebird'' (1952 film), a musical drama film directed by Hasse Ekman * "Fireb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Redis
Redis (; Remote Dictionary Server) is an in-memory key–value database, used as a distributed cache and message broker, with optional durability. Because it holds all data in memory and because of its design, Redis offers low- latency reads and writes, making it particularly suitable for use cases that require a cache. Redis is the most popular NoSQL database, and one of the most popular databases overall. The project was developed and maintained by Salvatore Sanfilippo, starting in 2009. From 2015 until 2020, he led a project core team sponsored by Redis Ltd. Salvatore Sanfilippo left Redis as the maintainer in 2020. In 2021 Redis Labs dropped the Labs from its name and now is known simply as "Redis". In 2018, some modules for Redis adopted a modified Apache 2.0 with a Commons Clause. In 2024, the main Redis code switched from the open-source BSD-3 license to being dual-licensed under the Redis Source Available License v2 and the Server Side Public License v1. On May ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Database Management System
In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a database system. Often the term "database" is also used loosely to refer to any of the DBMS, the database system or an application associated with the database. Before digital storage and retrieval of data have become widespread, index cards were used for data storage in a wide range of applications and environments: in the home to record and store recipes, shopping lists, contact information and other organizational data; in business to record presentation notes, project research and notes, and contact information; in schools as flash ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Column-oriented DBMS
Data orientation is the representation of tabular data in a linear memory model such as in-disk or in-memory. The two most common representations are column-oriented (columnar format) and row-oriented (row format). The choice of data orientation is a trade-off and an architectural decision in databases, query engines, and numerical simulations. As a result of these tradeoffs, row-oriented formats are more commonly used in Online transaction processing (OLTP) and column-oriented formats are more commonly used in Online analytical processing (OLAP). Examples of column-oriented formats include Apache ORC, Apache Parquet, Apache Arrow, formats used by BigQuery, Amazon Redshift and Snowflake. Predominant examples of row-oriented formats include CSV, formats used in most relational databases, the in-memory format of Apache Spark, and Apache Avro. Description Tabular data is two dimensional — data is modeled as rows and columns. However, computer systems represent d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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MonetDB
MonetDB is an open-source column-oriented relational database management system (RDBMS) originally developed at the Centrum Wiskunde & Informatica (CWI) in the Netherlands. It is designed to provide high performance on complex queries against large databases, such as combining tables with hundreds of columns and millions of rows. MonetDB has been applied in high-performance applications for online analytical processing, data mining, geographic information system (GIS), Resource Description Framework (RDF), text retrieval and sequence alignment processing. History Data mining projects in the 1990s required improved analytical database support. This resulted in a CWI spin-off called Data Distilleries, which used early MonetDB implementations in its analytical suite. Data Distilleries eventually became a subsidiary of SPSS in 2003, which in turn was acquired by IBM in 2009. MonetDB in its current form was first created in 2002 by doctoral student Peter Boncz and professor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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CouchDB
Apache CouchDB is an open-source document-oriented NoSQL database, implemented in Erlang. CouchDB uses multiple formats and protocols to store, transfer, and process its data. It uses JSON to store data, JavaScript as its query language using MapReduce, and HTTP for an API. CouchDB was first released in 2005 and later became an Apache Software Foundation project in 2008. Unlike a relational database, a CouchDB database does not store data and relationships in tables. Instead, each database is a collection of independent documents. Each document maintains its own data and self-contained schema. An application may access multiple databases, such as one stored on a user's mobile phone and another on a server. Document metadata contains revision information, making it possible to merge any differences that may have occurred while the databases were disconnected. CouchDB implements a form of multiversion concurrency control (MVCC) so it does not lock the database file during writ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Elasticsearch
Elasticsearch is a Search engine (computing), search engine based on Apache Lucene, a free and open-source search engine. It provides a distributed, Multitenancy, multitenant-capable full-text search engine with an HTTP web interface and schema-free JSON documents. Official clients are available in Java (programming language), Java, .NET Framework, .NET (C Sharp (programming language), C#), PHP (programming language), PHP, Python (programming language), Python, Ruby (programming language), Ruby and many other languages. According to the DB-Engines ranking, Elasticsearch is the most popular enterprise search engine. History Shay Banon created the precursor to Elasticsearch, called Compass, in 2004. While thinking about the third version of Compass he realized that it would be necessary to rewrite big parts of Compass to "create a scalable search solution". So he created "a solution built from the ground up to be distributed" and used a common interface, JSON over HTTP, suitable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Apache Solr
Solr (pronounced "solar") is an open-source enterprise-search platform, written in Java. Its major features include full-text search, hit highlighting, faceted search, real-time indexing, dynamic clustering, database integration, NoSQL features and rich document (e.g., Word, PDF) handling. Providing distributed search and index replication, Solr is designed for scalability and fault tolerance. Solr is widely used for enterprise search and analytics use cases and has an active development community and regular releases. Solr runs as a standalone full-text search server. It uses the Lucene Java search library at its core for full-text indexing and search, and has REST-like HTTP/XML and JSON APIs that make it usable from most popular programming languages. Solr's external configuration allows it to be tailored to many types of applications without Java coding, and it has a plugin architecture to support more advanced customization. Apache Solr is developed in an open, collaborat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Google App Engine
Google App Engine (also referred to as GAE or App Engine) is a cloud computing platform used as a service for developing and hosting web applications. Applications are sandboxed and run across multiple Google-managed servers. GAE supports automatic scaling for web applications, allocating more resources to the web application as the amount of requests increases. It was released as a preview in April 2008 and launched officially in September 2011. Applications written in Go, PHP, Java, Python, Node.js, .NET, and Ruby are supported by the App Engine, and other languages can be supported at an additional cost. The free version of the service offers a standard environment with limited resources. Fees are charged for additional storage, bandwidth, or instance hours. Features Google App Engine primarily supports Go, PHP, Java, Python, Node.js, .NET, and Ruby applications, although it can also support other languages via "custom runtimes". Python web frameworks that run ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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DBMS
In computing, a database is an organized collection of data or a type of data store based on the use of a database management system (DBMS), the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a database system. Often the term "database" is also used loosely to refer to any of the DBMS, the database system or an application associated with the database. Before digital storage and retrieval of data have become widespread, index cards were used for data storage in a wide range of applications and environments: in the home to record and store recipes, shopping lists, contact information and other organizational data; in business to record presentation notes, project research and notes, and contact information; in schools as flash card ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |