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Transaction (database)
A database transaction symbolizes a unit of work, performed within a database management system (or similar system) against a database, that is treated in a coherent and reliable way independent of other transactions. A transaction generally represents any change in a database. Transactions in a database environment have two main purposes: # To provide reliable units of work that allow correct recovery from failures and keep a database consistent even in cases of system failure. For example: when execution prematurely and unexpectedly stops (completely or partially) in which case many operations upon a database remain uncompleted, with unclear status. # To provide isolation between programs accessing a database concurrently. If this isolation is not provided, the programs' outcomes are possibly erroneous. In a database management system, a transaction is a single unit of logic or work, sometimes made up of multiple operations. Any logical calculation done in a consistent mode in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unit Of Work
A unit of work is a behavioral pattern in Software engineering, software development. Martin Fowler (software engineer), Martin Fowler has defined it as everything one does during a Business transaction management, business transaction which can affect the database. When the unit of work is finished, it will provide everything that needs to be done to change the database as a result of the work. A unit of work encapsulates one or more code Repository (software design pattern), repositories:de:Repository (Entwurfsmuster), [de] and a list of actions to be performed which are necessary for the successful implementation of Isolation (database systems), self-contained and Consistency (database systems), consistent data change. A unit of work is also responsible for handling Concurrency (computer science), concurrency issues, and can be used for Transaction processing, transactions and Stability pattern, stability patterns.:de:Steady State (Stabilitätsmuster), [de]{{citation, author=Mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database 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 cards ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mime-type
In information and communications technology, a media type, content type or MIME type is a two-part identifier for file formats and content formats. Their purpose is comparable to filename extensions and uniform type identifiers, in that they identify the intended data format. They are mainly used by technologies underpinning the Internet, and also used on Linux desktop systems. The Internet Assigned Numbers Authority (IANA) is the official authority for the standardization and publication of these classifications. Media types were originally defined in Request for Comments (MIME) Part One: Format of Internet Message Bodies (Nov 1996) in November 1996 as a part of the ''MIME (Multipurpose Internet Mail Extensions)'' specification, for denoting type of email message content and attachments; hence the original name, ''MIME type''. Media types are also used by other internet protocols such as HTTP, document file formats such as HTML, and the XDG specifications implemented by Linux ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serialization
In computing, serialization (or serialisation, also referred to as pickling in Python (programming language), Python) is the process of translating a data structure or object (computer science), object state into a format that can be stored (e.g. computer file, files in secondary storage devices, data buffers in primary storage devices) or transmitted (e.g. data streams over computer networks) and reconstructed later (possibly in a different computer environment). When the resulting series of bits is reread according to the serialization format, it can be used to create a semantically identical clone of the original object. For many complex objects, such as those that make extensive use of reference (computer science), references, this process is not straightforward. Serialization of object (computer science), objects does not include any of their associated Method (computer science), methods with which they were previously linked. This process of serializing an object is also c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Binary Large Object
Object storage (also known as object-based storage or blob storage) is a computer data storage approach that manages data as "blobs" or "objects", as opposed to other storage architectures like file systems, which manage data as a file hierarchy, and block storage, which manages data as blocks within sectors and tracks. Each object is typically associated with a variable amount of metadata, and a globally unique identifier. Object storage can be implemented at multiple levels, including the device level (object-storage device), the system level, and the interface level. In each case, object storage seeks to enable capabilities not addressed by other storage architectures, like interfaces that are directly programmable by the application, a namespace that can span multiple instances of physical hardware, and data-management functions like data replication and data distribution at object-level granularity. Object storage systems allow retention of massive amounts of unstructured data ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autocommit
In the context of data management, autocommit is a mode of operation of a database connection. Each individual database interaction (i.e., each SQL statement) submitted through the database connection in autocommit mode will be executed in its own transaction that is implicitly committed. A SQL statement executed in autocommit mode cannot be rolled back. Autocommit mode incurs per-statement transaction overhead and can often lead to undesirable performance or resource utilization impact on the database. Nonetheless, in systems such as Microsoft SQL Server, as well as connection technologies such as ODBC and Microsoft OLE DB, autocommit mode is the default for all statements that change data, in order to ensure that individual statements will conform to the ACID (atomicity-consistency-isolation-durability) properties of transactions. The alternative to autocommit mode (non-autocommit) means that the SQL client application itself is responsible for ending transactions explicitly v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rollback (data Management)
In database technologies, a rollback is an operation which returns the database to some previous state. Rollbacks are important for database integrity, because they mean that the database can be restored to a clean copy even after erroneous operations are performed. They are crucial for recovering from database server crashes; by rolling back any transaction which was active at the time of the crash, the database is restored to a consistent state. The rollback feature is usually implemented with a transaction log, but can also be implemented via multiversion concurrency control. Cascading rollback A cascading rollback occurs in database systems when a transaction (T1) causes a failure and a rollback must be performed. Other transactions dependent on T1's actions must also be rollbacked due to T1's failure, thus causing a cascading effect. That is, one transaction's failure causes many to fail. Practical database recovery techniques guarantee cascadeless rollback, therefore a cas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commit (SQL)
In computer science and data management, a commit is a behavior that marks the end of a transaction and provides Atomicity, Consistency, Isolation, and Durability (ACID) in transactions. The submission records are stored in the submission log for recovery and consistency in case of failure. In terms of transactions, the opposite of committing is giving up tentative changes to the transaction, which is rolled back. Due to the rise of distributed computing and the need to ensure data consistency across multiple systems, commit protocols have been evolving since their emergence in the 1970s. The main developments include the Two-Phase Commit (2PC) first proposed by Jim Gray, which is the fundamental core of distributed transaction management. Subsequently, the Three-phase Commit (3PC), Hypothesis Commit (PC), Hypothesis Abort (PA), and Optimistic Commit protocols gradually emerged, solving the problems of blocking and fault recovery. Today, new fields such as e-commerce paymen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MyISAM
MyISAM was the default storage engine for the MySQL relational database management system versions prior to 5.5 released in December 2009. It is based on the older ISAM code, but it has many useful extensions. Filesystem Each MyISAM table is stored on disk in three files (if it is not partitioned). The files have names that begin with the table name and have an extension to indicate the file type. MySQL uses a .frm file to store the definition of the table, but this file is not a part of the MyISAM engine; instead it is a part of the server. The data file has a .MYD (MYData) extension. The index file has a .MYI (MYIndex) extension. The index file, if lost, can always be recreated by recreating indexes. Files format depends on the ROW_FORMAT table option. The following formats are available: * FIXED: Fixed is a format where all data (including variable-length types) have a fixed length. This format is faster to read, and improves corrupted tables repair. If a table contains big ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
InnoDB
InnoDB is a storage engine for the database management system MySQL and MariaDB. Since the release of MySQL 5.5.5 in 2010, it replaced MyISAM as MySQL's default table type. It provides the standard ACID-compliant transaction features, along with foreign key support ( declarative referential integrity). It is included as standard in most binaries distributed by MySQL AB, the exception being some OEM versions. Description InnoDB became a product of Oracle Corporation after its acquisition of the Finland-based company Innobase in October 2005. The software is dual licensed; it is distributed under the GNU General Public License, but can also be licensed to parties wishing to combine InnoDB in proprietary software. InnoDB supports: * Both SQL and XA transactions * Tablespaces * Foreign keys * Full text search indexes, since MySQL 5.6 (February 2013) and MariaDB 10.0 * Spatial operations, following the OpenGIS standard * Virtual columns, in MariaDB MariaDB is a community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MySQL
MySQL () is an Open-source software, open-source relational database management system (RDBMS). Its name is a combination of "My", the name of co-founder Michael Widenius's daughter My, and "SQL", the acronym for Structured Query Language. A relational database organizes data into one or more data tables in which data may be related to each other; these relations help structure the data. SQL is a language that programmers use to create, modify and extract data from the relational database, as well as control user access to the database. In addition to relational databases and SQL, an RDBMS like MySQL works with an operating system to implement a relational database in a computer's storage system, manages users, allows for network access and facilitates testing database integrity and creation of backups. MySQL is free and open-source software under the terms of the GNU General Public License, and is also available under a variety of proprietary software, proprietary licenses. MySQ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compensating Transaction
Compensation may refer to: *Financial compensation Financial compensation refers to the act of providing a person with money or other things of economic value in exchange for their goods, labor, or to provide for the costs of injuries that they have incurred. The aim of financial compensation ... * Compensation (chess), various advantages a player has in exchange for a disadvantage * ''Compensation'' (essay), by Ralph Waldo Emerson * ''Compensation'' (film), a 1999 film * Compensation (psychology) * Biological compensation, the characteristic pattern of bending of the plant or mushroom stem after turning from the normal vertical position * Tuning compensation in brass instruments *''Compensation'', a specific form of camouflaging in autistic people See also *"Compensating", a song by Aminé from his 2020 album ''Limbo'' {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
