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NoSQL Products
NoSQL (originally meaning "Not only SQL" or "non-relational") refers to a type of database design that stores and retrieves data differently from the traditional table-based structure of relational databases. Unlike relational databases, which organize data into rows and columns like a spreadsheet, NoSQL databases use a single data structure—such as key–value pairs, wide columns, graphs, or documents—to hold information. Since this non-relational design does not require a fixed schema, it scales easily to manage large, often unstructured datasets. NoSQL systems are sometimes called ''"Not only SQL"'' because they can support SQL-like query languages or work alongside SQL databases in polyglot-persistent setups, where multiple database types are combined. Non-relational databases date back to the late 1960s, but the term "NoSQL" emerged in the early 2000s, spurred by the needs of Web 2.0 companies like social media platforms. NoSQL databases are popular in big data and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database
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 c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stale Read
Staling, or "going stale", is a chemical and physical process in bread and similar foods that reduces their palatability. Stale bread is dry and hard, making it less suitable for different culinary uses than fresh bread. Countermeasures and destaling techniques may reduce staling. Mechanism and effects Staling is a chemical and physical process in bread that reduces its palatability. Staling is not simply a drying-out process caused by evaporation. One important mechanism is the migration of moisture from the starch granules into the interstitial spaces, degelatinizing the starch; stale bread's leathery, hard texture results from the starch amylose and amylopectin molecules realigning and causing recrystallisation. Stale bread is dry and hard. Bread will stale even in a moist environment and stales most rapidly at temperatures just above freezing. While bread that has been frozen when fresh may be thawed acceptably, contrary to popular belief, bread stored in a refrigerator w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Database
A distributed database is a database in which data is stored across different physical locations. It may be stored in multiple computers located in the same physical location (e.g. a data centre); or maybe dispersed over a computer network, network of interconnected computers. Unlike Parallel computing, parallel systems, in which the processors are tightly coupled and constitute a single database system, a distributed database system consists of loosely coupled sites that share no physical components. System administrators can distribute collections of data (e.g. in a database) across multiple physical locations. A distributed database can reside on organised network servers or blockchain (database), decentralised independent computers on the Internet, on corporate intranets or extranets, or on other organisation Computer network, networks. Because distributed databases store data across multiple computers, distributed databases may improve performance at end-user worksites by all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Open Source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentralized software development model that encourages open collaboration. A main principle of Open-source software, open source software development is peer production, with products such as source code, blueprints, and documentation freely available to the public. The open source movement in software began as a response to the limitations of proprietary code. The model is used for projects such as in open source appropriate technology, and open source drug discovery. Open source promotes universal access via an open-source or free license to a product's design or blueprint, and universal redistribution of that design or blueprint. Before the phrase ''open source'' became widely adopted, developers and producers used a variety of other terms, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Last
A last is a mechanical form shaped like a human foot. It is used by shoemakers and cordwainers in the manufacture and repair of shoes. Lasts come in many styles and sizes, depending on the exact job they are designed for. Common variations include simple one-size lasts used for repairing soles and heels, custom-purpose mechanized lasts used in modern mass production, and custom-made lasts used in the making of bespoke footwear. Lasts are made of firm materialshardwoods, cast iron, and high-density plasticsto withstand contact with wetted leather and the strong forces involved in reshaping it. Since the early 19th century, lasts typically come in pairs to match the separate shapes of the right and left feet. The development of an automated lasting machine by the Surinamese-American Jan Ernst Matzeliger in the 1880s was a major development in shoe production, immediately improving quality, halving prices, and eliminating the previous putting-out systems surrounding shoema ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strozzi NoSQL (RDBMS)
Strozzi NoSQL is a shell-based relational database management system initialized and developed by Carlo Strozzi that runs under Unix-like operating systems, or others with compatibility layers (e.g., Cygwin under Windows). Its file name ''NoSQL'' merely reflects the fact that it does not express its queries using Structured Query Language; the NoSQL RDBMS is distinct from the circa-2009 general concept of NoSQL databases, which are typically non-relational, unlike the NoSQL RDBMS. Strozzi NoSQL is released under the GNU GPL The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first .... Construction NoSQL uses the operator-stream paradigm, where a number of "operators" perform a unique function on the passed data. The stream used is supplied by the UNIX input/output redirection system so th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operating System
An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for efficient use of the system and may also include accounting software for cost allocation of Scheduling (computing), processor time, mass storage, peripherals, and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is usually executed directly by the hardware and frequently makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computerfrom cellular phones and video game consoles to web servers and supercomputers. , Android (operating system), Android is the most popular operating system with a 46% market share, followed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X/Open XA
For transaction processing in computing, the X/Open XA standard (short for "eXtended Architecture") is a specification released in 1991 by X/Open (which later merged with The Open Group) for distributed transaction processing (DTP). Goals The goal of XA is to guarantee atomicity in "global transactions" that are executed across heterogeneous components. A ''transaction'' is a unit of work such as transferring money from one person to another. Distributed transactions update multiple data stores (such as databases, application servers, message queues, transactional caches, etc.). To guarantee integrity, XA uses a two-phase commit (2PC) to ensure that all of a transaction's changes either take effect (''commit'') or do not (''roll back''), i.e., ''atomically''. Architecture Specifically, XA describes the interface between a global transaction manager and a specific application. An application that wants to use XA engages an XA transaction manager using a library or separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distributed Transaction Processing
A distributed transaction operates within a distributed environment, typically involving multiple nodes across a network depending on the location of the data. A key aspect of distributed transactions is atomicity, which ensures that the transaction is completed in its entirety or not executed at all. It's essential to note that distributed transactions are not limited to databases. The Open Group, a vendor consortium, proposed the X/Open Distributed Transaction Processing Model (X/Open XA), which became a de facto standard for the behavior of transaction model components. Databases are common transactional resources and, often, transactions span a couple of such databases. In this case, a distributed transaction can be seen as a database transaction that must be synchronized (or provide ACID properties) among multiple participating databases which are distributed among different physical locations. The isolation property (the I of ACID) poses a special challenge for multi da ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Write-ahead Logging
In computer science, write-ahead logging (WAL) is a family of techniques for providing atomicity and durability (two of the ACID properties) in database systems. A write ahead log is an append-only auxiliary disk-resident structure used for crash and transaction recovery. The changes are first recorded in the log, which must be written to stable storage, before the changes are written to the database. The main functionality of a write-ahead log can be summarized as: * Allow the page cache to buffer updates to disk-resident pages while ensuring durability semantics in the larger context of a database system. * Persist all operations on disk until the cached copies of pages affected by these operations are synchronized on disk. Every operation that modifies the database state has to be logged on disk before the contents on the associated pages can be modified * Allow lost in-memory changes to be reconstructed from the operation log in case of a crash. In a system using WAL, all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Data Loss
Data loss is an error condition in information systems in which information is destroyed by failures (like failed spindle motors or head crashes on hard drives) or neglect (like mishandling, careless handling or storage under unsuitable conditions) in storage, transmission, or processing. Information systems implement backup and disaster recovery equipment and processes to prevent data loss or restore lost data. Data loss can also occur if the physical medium containing the data is lost or stolen. Data loss is distinguished from data unavailability, which may arise from a network outage. Although the two have substantially similar consequences for users, data unavailability is temporary, while data loss may be permanent. Data loss is also distinct from data breach, an incident where data falls into the wrong hands, although the term data loss has been used in those incidents. Types *''Procedural'' * ''Intentional action'' ** Intentional deletion of a file or program * ''Unin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Join (SQL)
A join clause in the Structured Query Language (SQL) combines column (database), columns from one or more table (database), tables into a new table. The operation corresponds to a Join (relational algebra), join operation in relational algebra. Informally, a join stitches two tables and puts on the same row records with matching fields : INNER, LEFT OUTER, RIGHT OUTER, FULL OUTER and CROSS. Example tables To explain join types, the rest of this article uses the following tables: Department.DepartmentID is the primary key of the Department table, whereas Employee.DepartmentID is a foreign key. Note that in Employee, "Williams" has not yet been assigned to a department. Also, no employees have been assigned to the "Marketing" department. These are the SQL statements to create the above tables: CREATE TABLE department( DepartmentID INT PRIMARY KEY NOT NULL, DepartmentName VARCHAR(20) ); CREATE TABLE employee ( LastName VARCHAR(20), DepartmentID INT REFERENCE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
