Lightning Memory-Mapped Database
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Lightning Memory-Mapped Database
Lightning Memory-Mapped Database (LMDB) is an embedded transactional database in the form of a key-value store. LMDB is written in C (programming language), C with #API and uses, API bindings for several programming languages. LMDB stores arbitrary key/data pairs as byte arrays, has a range-based search capability, supports multiple data items for a single key and has a special mode for appending records (MDB_APPEND) without checking for consistency.LMDB Reference Guide
Retrieved on 2023-03-21
LMDB is not a relational database, it is strictly a key-value store like Berkeley DB and DBM (computing), DBM. LMDB may also be used #Concurrency, concurrently in a multi-threaded or multi-processing environment, with read performance scaling linearly by design. LMDB databases may have only one writer at a time, however unlike many similar key-value databases, ...
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C (programming Language)
C (''pronounced'' '' – like the letter c'') is a general-purpose programming language. It was created in the 1970s by Dennis Ritchie and remains very widely used and influential. By design, C's features cleanly reflect the capabilities of the targeted Central processing unit, CPUs. It has found lasting use in operating systems code (especially in Kernel (operating system), kernels), device drivers, and protocol stacks, but its use in application software has been decreasing. C is commonly used on computer architectures that range from the largest supercomputers to the smallest microcontrollers and embedded systems. A successor to the programming language B (programming language), B, C was originally developed at Bell Labs by Ritchie between 1972 and 1973 to construct utilities running on Unix. It was applied to re-implementing the kernel of the Unix operating system. During the 1980s, C gradually gained popularity. It has become one of the most widely used programming langu ...
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Concurrency
Concurrent means happening at the same time. Concurrency, concurrent, or concurrence may refer to: Law * Concurrence, in jurisprudence, the need to prove both ''actus reus'' and ''mens rea'' * Concurring opinion (also called a "concurrence"), a legal opinion which supports the conclusion, though not always the reasoning, of the majority. * Concurrent estate, a concept in property law * Concurrent resolution, a legislative measure passed by both chambers of the United States Congress * Concurrent sentences, in criminal law, periods of imprisonment that are served simultaneously Computing * Concurrency (computer science), the property of program, algorithm, or problem decomposition into order-independent or partially-ordered units * Concurrent computing, the overlapping execution of multiple interacting computational tasks * Concurrence (quantum computing), a measure used in quantum information theory * Concurrent Computer Corporation, an American computer systems manufacturer * ...
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Endianness
file:Gullivers_travels.jpg, ''Gulliver's Travels'' by Jonathan Swift, the novel from which the term was coined In computing, endianness is the order in which bytes within a word (data type), word of digital data are transmitted over a data communication medium or Memory_address, addressed (by rising addresses) in computer memory, counting only byte Bit_numbering#Bit significance and indexing, significance compared to earliness. Endianness is primarily expressed as big-endian (BE) or little-endian (LE), terms introduced by Danny Cohen (computer scientist), Danny Cohen into computer science for data ordering in an Internet Experiment Note published in 1980. Also published at The adjective ''endian'' has its origin in the writings of 18th century Anglo-Irish writer Jonathan Swift. In the 1726 novel ''Gulliver's Travels'', he portrays the conflict between sects of Lilliputians divided into those breaking the shell of a boiled egg from the big end or from the little end. By analogy, ...
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Sparse File
In computer science, a sparse file is a type of computer file that attempts to use file system space more efficiently when the file itself is partially empty. This is achieved by writing brief information (metadata) ''representing'' the empty blocks to the data storage media instead of the actual "empty" space which makes up the block, thus consuming less storage space. The full block is written to the media as the actual size only when the block contains "real" (non-empty) data. Most commonly, sparse files are created when blocks of the file are never written to. This is typical for random-access files like databases. Some operating systems or utilities go further by "sparsifying" files when writing or copying them: if a block contains only null bytes, it is not written to storage but rather marked as empty. When reading sparse files, the file system transparently converts metadata representing empty blocks into "real" blocks filled with null bytes at runtime. The application is ...
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Copy-on-write
Copy-on-write (COW), also called implicit sharing or shadowing, is a resource-management technique used in programming to manage shared data efficiently. Instead of copying data right away when multiple programs use it, the same data is shared between programs until one tries to modify it. If no changes are made, no private copy is created, saving resources. A copy is only made when needed, ensuring each program has its own version when modifications occur. This technique is commonly applied to memory, files, and data structures. In virtual memory management Copy-on-write finds its main use in operating systems, sharing the physical memory of computers running multiple processes, in the implementation of the fork() system call. Typically, the new process does not modify any memory and immediately executes a new process, replacing the address space entirely. It would waste processor time and memory to copy all of the old process's memory during the fork only to immediately dis ...
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Reliability
Reliability, reliable, or unreliable may refer to: Science, technology, and mathematics Computing * Data reliability (other), a property of some disk arrays in computer storage * Reliability (computer networking), a category used to describe protocols * Reliability (semiconductor), outline of semiconductor device reliability drivers Other uses in science, technology, and mathematics * Reliability (statistics), the overall consistency of a measure * Reliability engineering, concerned with the ability of a system or component to perform its required functions under stated conditions for a specified time ** Human reliability in engineered systems * Reliability theory, as a theoretical concept, to explain biological aging and species longevity Other uses * Reliabilism, in philosophy and epistemology * Unreliable narrator, whose credibility has been seriously compromised See also * * * * Reliant (other) Reliant may also refer to: * Reliant Energy, an energy c ...
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Copy-on-write
Copy-on-write (COW), also called implicit sharing or shadowing, is a resource-management technique used in programming to manage shared data efficiently. Instead of copying data right away when multiple programs use it, the same data is shared between programs until one tries to modify it. If no changes are made, no private copy is created, saving resources. A copy is only made when needed, ensuring each program has its own version when modifications occur. This technique is commonly applied to memory, files, and data structures. In virtual memory management Copy-on-write finds its main use in operating systems, sharing the physical memory of computers running multiple processes, in the implementation of the fork() system call. Typically, the new process does not modify any memory and immediately executes a new process, replacing the address space entirely. It would waste processor time and memory to copy all of the old process's memory during the fork only to immediately dis ...
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Application Programming Interface
An application programming interface (API) is a connection between computers or between computer programs. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standard that describes how to build such a connection or interface is called an ''API specification''. A computer system that meets this standard is said to ''implement'' or ''expose'' an API. The term API may refer either to the specification or to the implementation. In contrast to a user interface, which connects a computer to a person, an application programming interface connects computers or pieces of software to each other. It is not intended to be used directly by a person (the end user) other than a computer programmer who is incorporating it into software. An API is often made up of different parts which act as tools or services that are available to the programmer. A program or a programmer that uses one of these parts is said to ''call'' that ...
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Performance
A performance is an act or process of staging or presenting a play, concert, or other form of entertainment. It is also defined as the action or process of carrying out or accomplishing an action, task, or function. Performance has evolved globally, from ancient rituals to modern artistic expressions. Expanding the article with historical and cultural perspectives would improve its scope. Ancient & Classical Theater: Rooted in rituals (Egyptian passion plays, Indigenous storytelling), early performances led to Greek tragedy, Sanskrit drama, and Chinese opera. Medieval & Early Modern Performance: Includes mystery plays in Europe, Commedia dell’arte in Italy, and Kabuki & Noh in Japan. Contemporary & Political Performance: Modern forms include agitprop theater, Forum Theater, and performance art as activism. By highlighting global traditions, the article would better reflect performance as a universal human expression shaped by history and culture. Management science In the ...
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B+ Tree
A B+ tree is an m-ary tree with a variable but often large number of children per node. A B+ tree consists of a root, internal nodes and leaves. The root may be either a leaf or a node with two or more children. A B+ tree can be viewed as a B-tree in which each node contains only keys (not key–value pairs), and to which an additional level is added at the bottom with linked leaves. The primary value of a B+ tree is in storing data for efficient retrieval in a Block (data storage), block-oriented storage context—in particular, filesystems. This is primarily because unlike binary search trees, B+ trees have very high fanout (number of pointers to child nodes in a node, typically on the order of 100 or more), which reduces the number of I/O operations required to find an element in the tree. History There is no single paper introducing the B+ tree concept. Instead, the notion of maintaining all data in leaf nodes is repeatedly brought up as an interesting variant of the B- ...
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