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NoSQL
A NoSQL (originally referring to "non- SQL" or "non-relational") database provides a mechanism for storage and retrieval of data that is modeled in means other than the tabular relations used in relational databases. Such databases have existed since the late 1960s, but the name "NoSQL" was only coined in the early 21st century, triggered by the needs of Web 2.0 companies. NoSQL databases are increasingly used in big data and real-time web applications. NoSQL systems are also sometimes called Not only SQL to emphasize that they may support SQL-like query languages or sit alongside SQL databases in polyglot-persistent architectures. Motivations for this approach include simplicity of design, simpler "horizontal" scaling to clusters of machines (which is a problem for relational databases), finer control over availability and limiting the object-relational impedance mismatch. The data structures used by NoSQL databases (e.g. key–value pair, wide column, graph, or docum ... [...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. 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 that over the pipe system, the result of the calculation can be passed to other operators. As UNIX pipes run in memory, it is a very efficient way of implementation. NoSQL, with development led by Carlo Strozzi, is the latest and perhaps the most acti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Document-oriented Database
A document-oriented database, or document store, is a computer program and data storage system designed for storing, retrieving and managing document-oriented information, also known as semi-structured data. Document-oriented databases are one of the main categories of NoSQL databases, and the popularity of the term "document-oriented database" has grown with the use of the term NoSQL itself. XML databases are a subclass of document-oriented databases that are optimized to work with XML documents. Graph databases are similar, but add another layer, the ''relationship'', which allows them to link documents for rapid traversal. Document-oriented databases are inherently a subclass of the key-value store, another NoSQL database concept. The difference lies in the way the data is processed; in a key-value store, the data is considered to be inherently opaque to the database, whereas a document-oriented system relies on internal structure in the ''document'' in order to extract met ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spans formal techniques and practical considerations, including data modeling, efficient data representation and storage, query languages, security and privacy of sensitive data, and distributed computing issues, including supporting concurrent access and fault tolerance. A database management system (DBMS) is the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS software 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 app ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph Database
A graph database (GDB) is a database that uses graph structures for semantic queries with nodes, edges, and properties to represent and store data. A key concept of the system is the '' graph'' (or ''edge'' or ''relationship''). The graph relates the data items in the store to a collection of nodes and edges, the edges representing the relationships between the nodes. The relationships allow data in the store to be linked together directly and, in many cases, retrieved with one operation. Graph databases hold the relationships between data as a priority. Querying relationships is fast because they are perpetually stored in the database. Relationships can be intuitively visualized using graph databases, making them useful for heavily inter-connected data. Graph databases are commonly referred to as a NoSQL. Graph databases are similar to 1970s network model databases in that both represent general graphs, but network-model databases operate at a lower level of abstraction and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon DynamoDB
Amazon DynamoDB is a fully managed proprietary NoSQL database service that supports key–value and document data structures and is offered by Amazon.com as part of the Amazon Web Services portfolio. DynamoDB exposes a similar data model to and derives its name from Dynamo, but has a different underlying implementation. Dynamo had a multi-leader design requiring the client to resolve version conflicts and DynamoDB uses synchronous replication across multiple data centers for high durability and availability. DynamoDB was announced by Amazon CTO Werner Vogels on January 18, 2012, and is presented as an evolution of Amazon SimpleDB. Background Werner Vogels, CTO at Amazon.com, provided a motivation for the project in his 2012 announcement. Amazon began as a decentralized network of services. Originally, services had direct access to each other's databases. When this became a bottleneck on engineering operations, services moved away from this direct access pattern in favor of pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bigtable
Bigtable is a fully managed wide-column and key-value NoSQL database service for large analytical and operational workloads as part of the Google Cloud portfolio. History Bigtable development began in 2004.. It is now used by a number of Google applications, such as Google Analytics, web indexing, MapReduce, which is often used for generating and modifying data stored in Bigtable, Google Maps,. Google Books search, "My Search History", Google Earth, Blogger.com, Google Code hosting, YouTube, and Gmail. Google's reasons for developing its own database include scalability and better control of performance characteristics. Google's Spanner RDBMS is layered on an implementation of Bigtable with a Paxos group for two-phase commits to each table. Google F1 was built using Spanner to replace an implementation based on MySQL. Apache HBase and Cassandra are some of the best known open source projects that were modeled after Bigtable. On May 6, 2015, a public version of Bigtable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wide-column Store
A wide-column store (or extensible record store) is a type of NoSQL database.Wide Column Stores DB-Engines Encyclopedia. It uses tables, rows, and columns, but unlike a relational database, the names and format of the columns can vary from row to row in the same table. A wide-column store can be interpreted as a two-dimensional key–value store. Wide-column stores versus columnar databases Wide-column stores such as and |
Relational Database
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relational database systems are equipped with the option of using the SQL (Structured Query Language) for querying and maintaining the database. History The term "relational database" was first defined by E. F. Codd at IBM in 1970. Codd introduced the term in his research paper "A Relational Model of Data for Large Shared Data Banks". In this paper and later papers, he defined what he meant by "relational". One well-known definition of what constitutes a relational database system is composed of Codd's 12 rules. However, no commercial implementations of the relational model conform to all of Codd's rules, so the term has gradually come to describe a broader class of database systems, which at a minimum: # Present the data to the user as re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CAP Theorem
In theoretical computer science, the CAP theorem, also named Brewer's theorem after computer scientist Eric Brewer, states that any distributed data store can provide only two of the following three guarantees:Seth Gilbert and Nancy Lynch"Brewer's conjecture and the feasibility of consistent, available, partition-tolerant web services" ''ACM SIGACT News'', Volume 33 Issue 2 (2002), pg. 51–59. . ; Consistency: Every read receives the most recent write or an error. ; Availability: Every request receives a (non-error) response, without the guarantee that it contains the most recent write. ; Partition tolerance: The system continues to operate despite an arbitrary number of messages being dropped (or delayed) by the network between nodes. When a network partition failure happens, it must be decided whether to do one of the following: * cancel the operation and thus decrease the availability but ensure consistency * proceed with the operation and thus provide availability but ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyglot Persistence
Polyglot persistence is a term that refers to using multiple data storage technologies for varying data storage needs across an application or within smaller components of an application. Such varying data storage needs could arise in both the cases, i.e. an enterprise with multiple applications or singular components of an application needing to store data differently. Description Polyglot persistence shares its origins with how the term Polyglot programming is defined. Polyglot programming is a term coined by Neal Ford in 2006, and expresses the idea that computer applications should be written in a mix of different programming languages, in order to take advantage of the fact that different languages are suitable for tackling different problems. Complex applications combine different types of problems, so picking the right language for each job may be more productive than trying to solve all aspects of the problem using a single language. This same concept can be applied to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horizontal Scaling
Scalability is the property of a system to handle a growing amount of work by adding resources to the system. In an economic context, a scalable business model implies that a company can increase sales given increased resources. For example, a package delivery system is scalable because more packages can be delivered by adding more delivery vehicles. However, if all packages had to first pass through a single warehouse for sorting, the system would not be as scalable, because one warehouse can handle only a limited number of packages. In computing, scalability is a characteristic of computers, networks, algorithms, networking protocols, programs and applications. An example is a search engine, which must support increasing numbers of users, and the number of topics it indexes. Webscale is a computer architectural approach that brings the capabilities of large-scale cloud computing companies into enterprise data centers. In mathematics, scalability mostly refers to closure ... [...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 * ''Uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
