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MySQL Archive
Archive is a storage engine for the MySQL relational database management system. Users can use this analytic storage engine to create a table that is “archive” only. Data cannot be deleted from this table, only added. The Archive engine uses a compression strategy based on the zlib library and it packs the rows using a bit header to represent nulls and removes all whitespace for character type fields. When completed, the row is inserted into the compression buffer and flushed to disk by an explicit flush table, a read, or the closing of the table. One of the current restrictions of Archive tables is that they do not support any indexes, thus necessitating a table scan for any SELECT tasks. Archive tables, however, are supported by the MySQL Query Cache, which can dramatically reduce response times for Archive table queries that are repetitively issued. MySQL is examining index support for Archive tables in upcoming releases. The engine is not ACID compliant. Unlike OLTP eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brian Aker
Brian Aker, born August 4, 1972, in Lexington, Kentucky, US, is an open-source hacker who has worked on various Apache modules, the Slash system, and numerous storage engines for the MySQL database. Aker was Director of Architecture at MySQL AB until it was acquired by Sun Microsystems. He led Sun's web scaling research group, where he worked on the Drizzle database project. He later became a Distinguished Engineer for Sun Microsystems. After leaving Sun when Oracle acquired it, he became the CTO of Data Differential and provided support to open source projects such as libmemcached, Gearman and the Drizzle database project. Aker is currently a Fellow and VP at Hewlett Packard Enterprise. After graduating with triple majors in environmental science, computing and mathematics, from Antioch College, Aker contributed to his first open source project, the 386BSD operating system. He then moved to work on Slashdot, where his initial task was to rewrite the database back-end to use O ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relational Database Management System
A relational database (RDB) is a database based on the relational model of data, as proposed by E. F. Codd in 1970. A Relational Database Management System (RDBMS) is a type of database management system that stores data in a structured format using rows and columns. Many relational database systems are equipped with the option of using SQL (Structured Query Language) for querying and updating the database. History The concept of relational database was defined by E. F. Codd at IBM in 1970. Codd introduced the term ''relational'' 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 ''relation''. 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiversion Concurrency Control
Multiversion concurrency control (MCC or MVCC), is a non-locking concurrency control method commonly used by database management systems to provide concurrent access to the database and in programming languages to implement transactional memory. Description Without concurrency control, if someone is reading from a database at the same time as someone else is writing to it, it is possible that the reader will see a half-written or inconsistent piece of data. For instance, when making a wire transfer between two bank accounts if a reader reads the balance at the bank when the money has been withdrawn from the original account and before it was deposited in the destination account, it would seem that money has disappeared from the bank. Isolation is the property that provides guarantees in the concurrent accesses to data. Isolation is implemented by means of a concurrency control protocol. The simplest way is to make all readers wait until the writer is done, which is known as a rea ... [...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] |
Gzip
gzip is a file format and a software application used for file compression and decompression. The program was created by Jean-loup Gailly and Mark Adler as a free software replacement for the compress program used in early Unix systems, and intended for use by GNU (from which the "g" of gzip is derived). Version 0.1 was first publicly released on 31 October 1992, and version 1.0 followed in February 1993. The decompression of the ''gzip'' format can be implemented as a streaming algorithm, an important feature for Web protocols, data interchange and ETL (in standard pipes) applications. File format gzip is based on the DEFLATE algorithm, which is a combination of LZ77 and Huffman coding. DEFLATE was intended as a replacement for LZW and other patent-encumbered data compression algorithms which, at the time, limited the usability of the compress utility and other popular archivers. "gzip" also refers to the gzip file format (described in the table below). In sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OLTP
Online transaction processing (OLTP) is a type of database system used in transaction-oriented applications, such as many operational systems. "Online" refers to the fact that such systems are expected to respond to user requests and process them in real-time (process transactions). The term is contrasted with online analytical processing (OLAP) which instead focuses on data analysis (for example planning and management systems). Meaning of the term transaction The term "transaction" can have two different meanings, both of which might apply: in the realm of computers or database transactions it denotes an atomic change of state, whereas in the realm of business or finance, the term typically denotes an exchange of economic entities (as used by, e.g., Transaction Processing Performance Council or commercial transactions.) OLTP may use transactions of the first type to record transactions of the second type. Compared to OLAP OLTP is typically contrasted to online analytical p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ACID
An acid is a molecule or ion capable of either donating a proton (i.e. Hydron, hydrogen cation, H+), known as a Brønsted–Lowry acid–base theory, Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid. The first category of acids are the proton donors, or Brønsted–Lowry acid–base theory, Brønsted–Lowry acids. In the special case of aqueous solutions, proton donors form the hydronium ion H3O+ and are known as Acid–base reaction#Arrhenius theory, Arrhenius acids. Johannes Nicolaus Brønsted, Brønsted and Martin Lowry, Lowry generalized the Arrhenius theory to include non-aqueous solvents. A Brønsted–Lowry or Arrhenius acid usually contains a hydrogen atom bonded to a chemical structure that is still energetically favorable after loss of H+. Aqueous Arrhenius acids have characteristic properties that provide a practical description of an acid. Acids form aqueous solutions with a sour taste, can turn blue litmus red, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zlib
zlib ( or "zeta-lib", ) is a software library used for data compression as well as a data format. zlib was written by Jean-loup Gailly and Mark Adler and is an abstraction of the DEFLATE compression algorithm used in their gzip file compression program. zlib is also a crucial component of many software platforms, including Linux, macOS, and iOS. It has also been used in gaming consoles such as the PlayStation 4, PlayStation 3, Wii U, Wii, Xbox One and Xbox 360. The first public version of Zlib, 0.9, was released on 1 May 1995 and was originally intended for use with the libpng image library. It is free software, distributed under the zlib License. Capabilities Encapsulation Raw DEFLATE compressed data (RFC 1951) are typically written with a zlib or gzip wrapper encapsulating the data, by adding a header and footer. This provides stream identification and error detection that are not provided by the raw DEFLATE data. The zlib wrapper (RFC 1950) is smaller than ... [...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] |
Cross-platform
Within computing, cross-platform software (also called multi-platform software, platform-agnostic software, or platform-independent software) is computer software that is designed to work in several Computing platform, computing platforms. Some cross-platform software requires a separate build for each platform, but some can be directly run on any platform without special preparation, being written in an interpreted language or compiled to portable bytecode for which the Interpreter (computing), interpreters or run-time packages are common or standard components of all supported platforms. For example, a cross-platform application software, application may run on Linux, macOS and Microsoft Windows. Cross-platform software may run on many platforms, or as few as two. Some frameworks for cross-platform development are Codename One, ArkUI-X, Kivy (framework), Kivy, Qt (software), Qt, GTK, Flutter (software), Flutter, NativeScript, Xamarin, Apache Cordova, Ionic (mobile app framework ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNU General Public License
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 copyleft license available for general use. It was originally written by Richard Stallman, the founder of the Free Software Foundation (FSF), for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. The GPL is more restrictive than the GNU Lesser General Public License, and even more distinct from the more widely used permissive software licenses such as BSD, MIT, and Apache. Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software (FOSS) domai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
