Timestamp-based concurrency controlIn computer science, a timestamp-based concurrency control algorithm is a non-lock concurrency control method. It is used in some databases to safely handle transactions, using timestamps. Every timestamp value is unique and accurately represents an instant in time. A higher-valued timestamp occurs later in time than a lower-valued timestamp. A number of different ways have been used to generate timestamp Use the value of the system's clock at the start of a transaction as the timestamp.
Genetically modified organismA genetically modified organism (GMO) is any organism whose genetic material has been altered using genetic engineering techniques. The exact definition of a genetically modified organism and what constitutes genetic engineering varies, with the most common being an organism altered in a way that "does not occur naturally by mating and/or natural recombination". A wide variety of organisms have been genetically modified (GM), from animals to plants and microorganisms.
CAP theoremIn 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: 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.
PessimismPessimism is a negative mental attitude in which an undesirable outcome is anticipated from a given situation. Pessimists tend to focus on the negatives of life in general. A common question asked to test for pessimism is "Is the glass half empty or half full?"; in this situation, a pessimist is said to see the glass as half empty, or in extreme cases completely empty, while an optimist is said to see the glass as half full. Throughout history, the pessimistic disposition has had effects on all major areas of thinking.
Core dumpIn computing, a core dump, memory dump, crash dump, storage dump, system dump, or ABEND dump consists of the recorded state of the working memory of a computer program at a specific time, generally when the program has crashed or otherwise terminated abnormally. In practice, other key pieces of program state are usually dumped at the same time, including the processor registers, which may include the program counter and stack pointer, memory management information, and other processor and operating system flags and information.
Crash (computing)In computing, a crash, or system crash, occurs when a computer program such as a software application or an operating system stops functioning properly and exits. On some operating systems or individual applications, a crash reporting service will report the crash and any details relating to it (or give the user the option to do so), usually to the developer(s) of the application. If the program is a critical part of the operating system, the entire system may crash or hang, often resulting in a kernel panic or fatal system error.
Network block deviceOn Linux, network block device (NBD) is a network protocol that can be used to forward a block device (typically a hard disk or partition) from one machine to a second machine. As an example, a local machine can access a hard disk drive that is attached to another computer. The protocol was originally developed for Linux 2.1.55 and released in 1997. In 2011 the protocol was revised, formally documented, and is now developed as a collaborative open standard. There are several interoperable clients and servers.
Windows 9xWindows 9x is a generic term referring to a series of Microsoft Windows computer operating systems produced from 1995 to 2000, which were based on the Windows 95 kernel and its underlying foundation of MS-DOS, both of which were updated in subsequent versions. The first version in the 9x series was Windows 95, which was succeeded by Windows 98 and then Windows Me, which was the third and last version of Windows on the 9x line, until the series was superseded by Windows XP. Windows 9x is predominantly known for its use in home desktops.
Object copyingIn object-oriented programming, object copying is creating a copy of an existing object, a unit of data in object-oriented programming. The resulting object is called an object copy or simply copy of the original object. Copying is basic but has subtleties and can have significant overhead. There are several ways to copy an object, most commonly by a copy constructor or cloning. Copying is done mostly so the copy can be modified or moved, or the current value preserved.
