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Definition of: Altair
A microcomputer kit introduced in late 1974 from Micro Instrumentation and Telemetry Systems (MITS). It sold for $400 and used an 8080 microprocessor. In 1975, it was packaged with the Microsoft MBASIC interpreter written by Paul Allen and Bill Gates. Although computer kits were advertised earlier by others, an estimated 10,000 Altairs were sold, making it the first commercially successful microcomputer.
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Bill gates programming languages?
None. He sew from others, buy, steal, blackmale or something nasty and sell :)
Who is known as the father of modern digital computers and why?
Charles Babbage was considered to be the father of computing after his invention and concept of the Analytical Engine in 1837. The Analytical Engine contained an Arithmetic Logic Unit (ALU), basic flow control, and integrated memory; hailed as the first general-purpose computer concept.
What are the causes and the effects of the computer revolution?
mga kupal kayo Hindi ko alam 2 kaya ko nga tinatanong ehHe/she said.... The kung you do not know 2 so i asked that ehDatePlaceEvent1950SepGERKonrad Zuse sells his Z4 machine to ETH Zurich.1950UKTuring Test - The British mathematician and computer pioneer Alan Turing published a paper describing the potential development of human and computer intelligence and communication. The paper would come later to be called the Turing Test.1950UKThe Pilot ACE computer, with 800 vacuum tubes, and mercury delay lines for its main memory, became operational on May 10, 1950 at the National Physical Laboratory near London. It was a preliminary version of the full ACE, which had been designed by Alan Turing.1950USATIME magazine cover story on the Harvard "Mark III: Can man build a superman?" includes a quote from Howard Aiken, commenting on "calculators" (computers) then under construction: "We'll have to think up bigger problems if we want to keep them busy."1951USAEDVAC becomes operational.1951Mar 30USAThe first commercially successful electronic computer, UNIVAC, was also the first general purpose computer - designed to handle both numeric and textual information. Designed by J. Presper Eckert and John Mauchly, whose corporation subsequently passed to Remington Rand. The implementation of this machine marked the real beginning of the computer era. Remington Rand delivered the first UNIVAC machine to the U.S. Bureau of Census. This machine used magnetic tape for input.1951Apr 21USAWhirlwind, the first real-time computer was built at MIT by the team of Jay Forrester for the US Air Defense System, became operational.This computer is the first to allow interactive computing, allowing users to interact with it using a keyboard and a cathode-ray tube. The Whirlwind design was later developed into SAGE, a comprehensive system of real-time computers used for early warning of air attacks.1951Nov 17UKJ Lyons, a United Kingdom food company, famous for its tea, made history by running the first business application on an electronic computer. A payroll system was run on Lyons Electronic Office (LEO) a computer system designed by Maurice Wilkes who had previously worked on EDSAC.1951AutumnUKThe oldest known recordings of computer generated music were played by the Ferranti Mark 1 computer.The Mark 1 is a commercial version of the Baby Machine from the University of Manchester. The music program was written by Christopher Strachey.1951USAEDVAC (electronic discrete variable computer). The first computer to use Magnetic Tape.EDVAC could have new programs loaded from the tape. Proposed by John von Neumann, it was installed at the Institute for Advance Study, Princeton, USA.1951AUSCSIRAC used to play music - the first time a computer was used as a musical instrument.1951USAThe A-0 high level compiler is invented by Grace Murray Hopper.1952USAIAS machine completed at the Institute for Advanced Study, Princeton, USA (by Von Neumann and others).1953UKThe University of Manchester team complete the first transistorised computer.1953USAArthur Andersen was hired to program the payroll for General Electric (GE)'s Appliance Park manufacturing facility near Louisville, Kentucky. As a result, GE purchased UNIVAC I which became the first-ever commercial computer in the United States. Joe Glickauf was Arthur Andersen's project leader for the GE engagement.1953WorldEstimate that there are 100 computers in the world.1953USAMagnetic core memory developed.1954USAFORTRAN (FORmula TRANslation), the first high-level programming language development, was started by John Backus and his team at IBMThe development continued until 1957. It is still in use for scientific programming. Before being run, a FORTRAN program needs to be converted into a machine program by a compiler, itself a program.1954USAThe NORC was built by IBM for the US Navy.1956USAFirst conference on Artificial Intelligence held at Dartmouth College in New Hampshire.1956USAThe Bendix G-15 computer was introduced by the Bendix Corporation1956NEDEdsger Dijkstra invented an efficient algorithm for shortest paths in graphs as a demonstration of the abilities of the ARMAC computer. The example used was the Dutch railway system. The problem was chosen because it could be explained quickly and the result checked. Although this is the main thing many people will remember Dijkstra for, he also made important contributions to many areas of computing - in particular he should be remembered for his work on problems relating to concurrency, such as the invention of the semaphore.1957USAFirst dot matrix printer marketed by IBM.1957USAFORTRAN development finished. See 1954.1957USAI have travelled the length and breadth of this country and talked with the best people, and I can assure you that data processing is a fad that won't last out the year.-Editor in charge of business books for Prentice Hall.1958USALISP (interpreted language) developed, Finished in 1960. LISP stands for 'LISt Processing'. Used in A.I. development. Developed by John McCarthy at Massachusetts Institute of Technology.1958Sep 12USAThe integrated circuit invented by Jack Kilby at Texas Instruments.Robert Noyce, who later set up Intel, also worked separately on the invention. Intel later went on to perfect the microprocessor. The patent was applied for in 1959 and granted in 1964. This patent wasn't accepted by Japan so Japanese businesses could avoid paying any fees, but in 1989 - after a 30 year legal battle - Japan granted the patent; so all Japanese companies paid fees up until the year 2001 - long after the patent became obsolete in the rest of the World.1959USAComputers built between 1959 and 1964 are often regarded as 'Second Generation' computers, based on transistors and printed circuits - resulting in much smaller computers. More powerful, the second generation of computers could handle compilers for languages such as FORTRAN (for science) or COBOL (for business), that accepting English-like commands, and so were much more flexible in their applications.1959USACOBOL (COmmon Business-Oriented Language) developed by Grace Murray Hopper as the successor to FLOW-MATIC, finished in 1961.1959USSRMinsk mainframe computer development and production started in the USSR. Stopped in 1975.1960sDatePlaceEvent1960USA EURALGOL - first structured, procedural, programming language to be released.1960UKCompiler compiler - The first compiler compiler is released.1960SRBCER-10 - vacuum tube-based computer created by Mihajlo Pupin Institute of Serbia, first computer in SFRY.1961USAAPL programming language released by Kenneth Iverson at IBM.1962UKATLAS is completed by the University of Manchester team.This machine introduced many modern architectural concepts: spooling, interrupts, pipelining, interleaved memory, virtual memory and paging. It was the most powerful machine in the world at the time of release.1962USAWork started on the Linc, the brainchild of the M.I.T. physicist Wesley A. Clark in May 1961. It was the first functional prototype of a computer scaled down to be optimized and priced for the individual user. Used for the first time at the National Institutes of Mental Health in Bethesda, Maryland in 1963, many consider it to be the first personal computer.1962USASpacewar!, the first computer game is written by MIT student Steve Russell.The game ran on a DEC PDP-1, competing players fired at each others space ships using an early version of joystick.1962?The AN/UYK-1 computer was designed with rounded edges to fit through the hatch of Ballistic missile submarines, as part of the first Satellite navigation system, Transit.1963USAMouse conceived by Douglas EngelbartThe Mouse was not to become popular until 1983 with Apple Computer's Macintosh and not adopted by IBM until 1987 - although compatible computers such as the Amstrad PC 1512 were fitted with mice before this date.1964USAComputers built between 1964 and 1972 are often regarded as 'Third Generation' computers, they are based on the first integrated circuits - creating even smaller machines. Typical of such machines was the IBM System/360 series mainframe, while smaller minicomputers began to open up computing to smaller businesses.1964USAProgramming language PL/I released by IBM.1964USALaunch of IBM System/360 - the first series of compatible computers. Over 14,000 were shipped by 1968.1964USAProject MAC is started at MIT by J.C.R. Licklider:several terminals all across campus will be connected to a central computer, using a timesharing mechanism. Bulletin boards and email are popular applications.1964SRBCER-20 released by Mihajlo Pupin Institute of Serbia as "electronic bookkeeping machine".1965USADEC PDP-8 Mini Computer. The first minicomputer, built by Digital Equipment (DEC). It cost $16,000.1965USAMoore's law published by Gordon Moore. Originally suggesting processor complexity doubled every year.It was published in the 35th Anniversary edition of Electronics magazine. The law was revised in 1975 to suggest a doubling in complexity every two years.1965USAFuzzy logic designed by Lofti Zadeh (University of California, Berkeley), it is used to process approximate data - such as 'about 100'.1965USSRBESM-6 mainframe computer was designed in the USSR.1965USABASIC programming language (Beginners All Purpose Symbolic Instruction Code) developed at Dartmouth College, USA, by Thomas E. Kurtz and John Kemeny.BASIC was not implemented on microcomputers until 1975. This was the first language designed to be used in a time-sharing environment, such as DTSS (Dartmouth Time-Sharing System), or GCOS.1965USAPacket switching, funded by ARPA was developed. This makes reliable computer networking possible.The first computer-to-computer login does not occur until November 21, 1969, between Stanford and UCLA.1965USAThe first supercomputer, the Control Data CDC 6600, was developed.1966USAHewlett-Packard entered the general purpose computer business with its HP-2115 for computation, offering a computational power formerly found only in much larger computers. It supported a wide variety of languages, among them BASIC, Algol, and FORTRAN.1966SRBCER-200 released by Mihajlo Pupin Institute of Serbia1967USADevelopment on the programming language Pascal started, to be finished in 1971. Based on Algol. Developed by Niklaus Wirth as a pedagogical tool.1967USAThe floppy disk is invented at IBM by David Noble,under the direction of Alan Shugart, for use with the System/370. License royalties are paid to Doctor Yoshiro Nakamatsu in Tokyo, who claimed he got the idea for the floppy disk in 1950.1967SRBCER-22 - first transistor-based computer created by Mihajlo Pupin Institute of Serbia, SFRY.1968USAIntel founded by Robert Noyce and a few friends.1968USALOGO programming language developed by Seymour Papert and team at MIT.1968USA"But what ... is it good for?"-Engineer at the Advanced Computing Systems Division of IBM commenting on the microchip.1968USADouglas Engelbart demonstrates interactive computing,at the Fall Joint Computer Conference in San Francisco: mouse, on-screen windows, hypertext and full-screen word processing.1969USAARPANET started by the United States Department of Defense for research into networking.It is the original basis for what now forms the Internet. It was opened to non-military users later in the 1970s and many universities and large businesses went on-line.1969Apr 7USAThe first Request for Comments, RFC 1 published. The RFCs (network working group, Request For Comment) are a series of papers which are used to develop and define protocols for networking; originally the basis for ARPANET, there are now thousands of them applying to all aspects of the Internet. Collectively they document everything about the way the Internet and computers on it should behave, whether its TCP/IP networking or how email headers should be written there will be a set of RFCs describing it.1969?Introduction of the RS-232 (serial interface) standard by EIA (Electronic Industries Association), one of the oldest serial interfaces still in common use today.1969USAData General shipped a total of 50,000 Novas at $8000 each. The Nova was one of the first 16-bit minicomputers and led the way toward word lengths that were multiples of the 8-bit byte. It was first to employ medium-scale integration (MSI) circuits from Fairchild Semiconductor, with subsequent models using large-scale integrated (LSI) circuits. Also notable was that the entire central processor was contained on one 15-inch printed circuit board.1970sDatePlaceEvent1970 OctUSAFirst dynamic[citation needed] RAM chip introduced by Intel. It was called the 1103 and had a capacity of 1 K-bit, 1024 bits.1970USADevelopment of UNIX operating system started.It was later released as C source code to aid portability, and subsequently versions are obtainable for many different computers, including the IBM PC. It and its clones (such as GNU/Linux) are still widely used on network servers and scientific workstations. Originally developed by Ken Thompson and Dennis Ritchie.1970USAForth programming language developed. A simple, clean, stackbased design, which later inspired PostScript and the Java virtual machine.1970JunUSASteve Geller, Ray Holt and a team from AiResearch and American Microsystems completed development of a flight data processor for the US Navy's F-14A Tomcat fighter jet. The processor used LSI chips to produce a fast, powerful, and rugged programmable computer that fitted into the very tight space restrictions of the aircraft.1970JunUSACTC creates the Datapoint 2200, a mass-produced programmable terminal. Its multi-chip CPU provided the basis for the Intel 8008; a monitor and tape drives were built-in, and the entire system fit the approximate footprint of an IBM Selectric typewriter. Users quickly began to use the system as a standalone computer; the unit is the earliest known which strongly resembles the personal computers of the 1980s and beyond.1971USARay Tomlinson develops the first program that can send email messages from one computer to another.1971Nov 15USAFirst microprocessor, the 4004, developed by a team at Intel, was released.It contains the equivalent of 2300 transistors and was a 4 bit processor. It is capable of around 60,000 instructions per second (0.06 MIPS), running at a maximum clock speed of 740 kHz.1971USATexas Instruments releases the first easily portable electronic calculator.1971SRBHRS-100, a hybrid computer system, released by Mihajlo Pupin Institute of Serbia1972USAAtari founded by Nolan Bushnell and Ted Dabney, (see also 1972).1972USAPong released - widely recognised as the first popular arcade video game. It was invented by Allan Alcorn.1972?Computers built after 1972 are often called 'fourth generation' computers, based on LSI (Large Scale Integration) of circuits (such as microprocessors) - typically 500 or more components on a chip. Later developments include VLSI (Very Large Scale Integration) of integrated circuits 5 years later - typically 10,000 components. The fourth generation is generally viewed as running right up until the present, since although computing power has increased the basic technology has remained virtually the same.1972USAC programming language developed at The Bell Laboratories in the USA by Dennis Ritchie(one of the inventors of the Unix operating system), its predecessor was the B programming language - also from Bell. It is a very popular language, especially for systems programming - as it is flexible and fast. C was considered a refreshing change in the computing industry because it helped introduce structured programming. The successor to C, C++, was introduced in the 1980s, and in turn helped usher in the era of Object oriented programming.1972USAFirst handheld scientific calculator released by Hewlett-Packard, the engineer's slide rule is at last obsolete.1972Apr 1USA8008 microprocessor released by Intel.1972USAThe first international connections to ARPANET are established. ARPANET later became the basis for what we now call the Internet.1972NORNorsk Data launches the Nord-5, the first 32-bit supermini computer.1973USADevelopment of the TCP/IP protocol suite by a group headed by Vinton Cerf and Robert E. Kahn. These are the protocols used on the internet.1973FRAProlog developed at the University of Luminy-Marseilles in France by Alain Colmerauer. It introduced the new paradigm of logical programming and is often used for expert systems and AI programming.1973USAThe TV Typewriter, designed by Don Lancaster, provided the first display of alphanumeric information on an ordinary television set. It used $120 worth of electronics components. The original design included two memory boards and could generate and store 512 characters as 16 lines of 32 characters. A 90-minute cassette tape provided supplementary storage for about 100 pages of text.1973USAEthernet developed, this became a popular way of connecting PCs and other computers together - to enable them to share data, and devices such as printers. A group of machines connected together in this way is known as a LAN.1974?CLIP-4, the first computer with a parallel architecture.1974CANMCM/70, the first personal computer to be commercially released, by Micro Computer Machines in Canada. Although it incorporated a plasma display, was programmable in the high level language APL, and weighed just 20 pounds, it failed commercially.1974Apr 1USAIntroduction of the 8080. It ran at a clock frequency of 2 MHz and did 0.64 MIPS.1974USAMotorola announces the MC6800 8 Bit Microprocessor. It is more easy to implement than the 8080 because it only needs a single power supply to operate and does not need support chips. Unlike the 8080 it is sold not as much as a general purpose "number cruncher / computer" CPU core but more as a control processor for industrial control and as a peripheral processor.1974USAEngineers Chuck Peddle and Bill Mensch leave Motorola after completing work on the 6800 CPU and join MOS Technology, Inc.1974Oct 9UKICL launches its New Range of mainframes, the ICL 2900 Series1974DecUSAThe MITS Altair 8800, the third commercially available personal computer, is released. In December 1974, an article in Popular Electronics invited people to order kits for the computer. Despite the limited memory (256 bytes) and limited processing power, around 200 were ordered on the first day. 10,000 were shipped at a kit price of $397 each. The Altair bus later developed into an industry standard, the S-100 bus.1975USAFirst microcomputer implementation of BASIC by Bill Gates and Paul Allen, it was written for the MITS Altair - the first personal computer - this led to the formation of Microsoft later in the year.1975USAUnix marketed (see 1970).1975NORNorwegian company Mycron releases its MYCRO-1, the first single-board computer.1975USAFormation of Microsoft by Bill Gates and Paul Allen.1975USAMOS Technology, Inc. releases their 6501 CPU. which is pin compatible with Motorola's 6800, who soon starts a lawsuit against them. The 6501 is quickly withdrawn from sale and replaced with the 6502 which has a "lawsuit-compatible"[1] design, but is otherwise nearly identical to the 6501.The 6502 becomes one of the most popular CPUs for the next 10 years and is used in many computers and game consoles (most notably the Atari 2600, Apple II, the Commodore PET, VIC-20 and Commodore 64, the Acorn Electron/BBC Microcomputer, and the Nintendo Entertainment System/NES).1975USAIBM 5100 computer released; with integrated keyboard, display, and mass storage on tape, it resembles the personal computers of a few years later, although it does not use a microprocessor.1975NovUSAZilog is founded by ex-Intel employees.1976Apr 1USAApple Computer, Inc. founded, to market the Apple I single-board computer designed by Steve Wozniak and Steve Jobs.It uses the MOS Technology 6502 microprocessor.1976USAFirst laser printer introduced by IBM - the IBM 3800.The first colour versions came onto the market in 1988.1976USAIntroduction of the Intel 8085 chip. An improved version of the 8080, with a superset of the 8080s instruction set (only a couple of extra instructions). Single 5V power supply (while the 8080 needed several different voltages).1976USAZ80 chip released by Zilog. It was a superset of the 8080 chip with additional registers and instructions, and using only one power supply voltage. CP/M was originally written for the 8080, but many implementations used the Z80. The Z80 was the processor for home computers like the Tandy TRS-80 of 1977, the Sinclair ZX Spectrum of 1982 and many others.1976USAMOS Technology, Inc introduces the KIM-1 microcoputer system as a demonstrator for its 6502 CPU.1976USACray-1 supercomputer was invented by Seymour Cray.He left Control Data in 1972 to form his own company. This machine was known as much for its horseshoe-shaped design as it was for being the first super to make vector processing practical. 85 were shipped at a cost of $5 million each.1976USACommodore buys MOS Technology, Inc in a stock trade. MOS is valued at $12 million. Chuck Peddle joins Commodore as chief engineer. With the purchase of MOS, Commodore begins work on the Commodore PET.1977USACommodore introduces the Commodore PET. It comes with 4KB or 8KB of RAM, and an integrated cassette deck and 9" monochrome monitor.1977USA"There is no reason anyone would want a computer in their home."-Ken Olsen, president, chairman and founder of Digital Equipment Corporation.1977Jun 5USAApple II computer introduced based on an 8 bit MOS Technology 6502 microprocessor running at 1 MHz microprocessor with 4 KB of RAM. It had an open architecture, used color graphics, and an audio cassette interface for loading programs and storing data. Later, in July 1978, a floppy disk drive was made available with an elegantly designed interface.[2] One of the first examples of a "killer app" (for the business world) was released for it-the VisiCalc spreadsheet program-in 1979.1977AugUSATandy brought out the TRS-80 with "Level I BASIC". Although the TRS-80 had a primitive 4K BASIC (a stripped down version of the public domain "Li-Chen Wang Basic") and abysmal graphics it still became a bestseller quickly.1977SepUSAHeathkit made the H8 Home computer kit available. It was based on an Intel 8080a processor and shipped with HDOS a Heathkit Disk Operating System and Benton Harbor BASIC. It was a kit.1978USATandy upgraded the TRS-80 with a much improved Microsoft 8K "Level II BASIC", and an "expansion interface" which added 32KB RAM, A floppy disk and a printer interface. With these extras the TRS-80 became a viable small business computer.1978Jun 8USAIntroduction of the 16-bit Intel 8086, the first x86 microprocessor. The available clock frequencies were 5, 8 and 10 MHz, with an instruction set of about 300 operations. At its introduction, the fastest 8086 available was the 8 MHz version which achieved 0.8 MIPS and contained 29,000 transistors. Over three decades later, x86 remains the most popular and commercially successful instruction set architecture in the history of personal computing.1978JAPThe Arcade Video game 'Space Invaders' is released, sparking a video game craze. In 1979, Atari's Asteroids would prove to be incredibly popular.1979USAAda programming language introduced by Jean Ichbiah and team at Honeywell for the US Department of Defense.1979Jun 1USAIntroduction of the Intel 8088, compatible with the 8086 with an 8-bit data bus - but this makes it cheaper to implement in computers. Chosen for the IBM PC, Intel processors were found in millions of IBM-PC compatible computers.1979UKCommodore PET released in the United Kingdom. Based on a 1 MHz 6502 processor it displayed monochrome text and had just 8 KB of RAM. Priced £569. For £776 you could purchase a version with 16 KB of RAM, while for £914 you could get a 32 KB of RAM.1979NEDJAPCompact disc was invented.1979USAThe 68000 Microprocessor launched by Motorola, the first of the 68k family. 5+ years later it was used in machines such as the Apple Macintosh, the Atari ST and the Commodore Amiga.1979USAShortly after the release of V7 Unix, which included UUCP, a protocol for communication over standard telephone lines, Tom Truscott and Jim Ellis created Usenet, a global discussion group system. Nowadays, it uses Internet protocols and is still popular.1979USAFour disgruntled Atari programmers leave and form Activision, the first third-party video game software publisher. Activision promotes both the game and the programmer, changing the way software is marketed.1979USAThe IBM PC. IBM saw its computer market dominance being eaten into by the new personal computers, such as the Apple II and the Commodore PET. IBM therefore started work on its own personal computer. When finished, this computer was released as the IBM PC on 12 August 19811979USATexas Instruments releases the TI-99/4 microcomputer. This system generally used audio cassettes to store information, along with ROM modules, similar to gaming units, to hold commercial software. Additionally, TI made available a speech synthesizer, based around their own chip, for the TI-99/4 and its successor, the 4A.
Advanced technics in rdbms?
1. Introduction One of the goals of benchmarks is to compare several database management systems on the same class of applications in order to show which one is more efficient for this particular class. Benchmarks used in the industry today are always oriented towards uncovering a defined limited set of features that a database should implement efficiently in order to successfully support the class of applications the benchmark was created for. One of the first industry benchmarks, the TP1 benchmark [1], developed by IBM purported to measure the performance of a system handling ATM transactions in a batch mode. Both TPC-C and TPC-D have gained widespread acceptance as the industry's premier benchmarks in their respective fields (OLTP and Decision Support). TPC-E failed to garner enough support because being an enterprise benchmark, it was only relevant to a relatively small number of companies competing in that space [11]. The Simple Database Operations Benchmark [9], Altair Complex-Object Benchmark [14], OO1 [6] and OO7 [3, 2] Benchmarks were created to provide useful insight for end-users evaluating the performance of Object Oriented Database Management Systems (OODBMS). Most object-relational DBMS are build on top of relational database by adding the following four key features [12]: inheritance, complex object support, an extensible type system, and triggers. The appearance of such databases necessitated the creation of the BUCKY benchmark [4], which tests most of these specific 2 features. It emphasizes those features of object-relational databases that are not covered by pure relational databases. 1.1 Semantic Model The semantic database models in general, and the Semantic Binary Model SBM [8, 10] in particular, represent information as a collection of elementary facts categorizing objects or establishing relationships of various kinds between pairs of objects. The facts in the database are of three types: facts stating that an object belongs to a category; facts stating that there is a relationship between objects; and facts relating objects to values. The relationships can be multivalued. The objects are categorized into classes according to their common properties. These classes, called categories, need not be disjoint; that is, one object may belong to several of them. Further, an arbitrary structure of subcategories and supercategories can be defined. 1.2 Why a Different Benchmark Unfortunately, most benchmarks do not provide general problem statement; instead they enforce a specific implementation that can not be efficiently translated to a different data model. For example, TPC benchmarks compares the efficiency of implementation of the same solution for different relational DBMS'es rather then comparing how efficiently DBMS'es are able to solve a given problem. The benchmark proposed does not enforce specific implementation thus allow native, efficient implementation for any DBMS - semantic, relational or any other, which makes it highly portable [7]. Majority of existing benchmarks is designed to evaluate features native to relational DBMS'es and none of them are suitable to evaluate performance of the features characteristic of semantic database applications. The benchmark proposed evaluates the ability of DBMS to efficiently support such features including sparse data, complex inheritances, many-to-many relations and variable field length. The rest of the paper is organized as follows: The benchmark application and the requirements for execution of transactions are defined in general terms in sections 2, 5, 6 and 7. Sections 3 and 4 describe our implementations of this application for semantic and relational database respectively. Section 8 presents the results we obtained for a semantic and a relational database and analyses the results. Conclusions are provided in section 9. 2. The Problem Stated It has recently become a practice for many consumer organizations to conduct consumer surveys. A large number of survey forms are mailed out to people and small companies with questions about shopping preferences in order to determine consumer patterns. Some consumers will fill out the survey and mail it back. The results of the survey should be stored in a database. Our survey collects information about several types of legal persons. It is mailed to physical persons and corporations and we keep information about all the legal persons the survey was mailed to. Those who answer the survey and mail it back are considered consumers and categorized into the corresponding category. We also try to collect referrals from people to their friends and mail our survey to the referred people. We remember the information about referrals so that we can explore correlation between groups of people who know each other. A person may refer another person without filling out the survey and thus without becoming a consumer as we define it. 3 Among the other questions, we will ask a consumer which stores does he prefer to shop at. We will thus keep a catalog of stores with their names and types (pharmacy, mass merchandiser, etc.) A consumer may list several stores he usually shops at, so that many-to-many relationship is established between consumers and stores. We will also ask a consumer to tell us his approximate annual expenditures in thousands of dollars and a list of his hobbies. We will collect information about ten types of products. Consumers will fall into different categories based on their answers about which products they regularly consume, for example "coffee drinker." We will mail them a survey where they will tell us if they regularly consume some product and answer questions about different brands they consume within each product group. Each product group in our survey has 10 brands. A consumer will tell us, which brands of the product he uses and show his preference of different brands in terms of a satisfaction rating of 1 to 4. Some consumers may indicate that they use this type of product, but none of the brands listed by us. This option should also be accommodated. We will also let a consumer write any comment about any brand he is using (from the ten brands we are asking about) if he wishes to do so. In practice, consumers seldom write any comments, so this information will be sparse. However, if they do write a comment it can be of any length and will probably be rather long. 3. A Semantic Schema for the Benchmark Database The benchmark deals with persons and corporations. Person and corporation are represented by two different categories with the appropriate personal attributes. They both inherit from a category Legal Person. A category Consumer, will inherit from Legal Person, since both persons and corporations may be consumers and there is no need to distinguish between them as consumers. Since the same object can not be both a person and a corporation, categories Person and Corporation will be set up as disjoint. A legal person who answered our survey becomes a consumer. The category Consumer will then be used to capture information about such legal persons as consumers. The attribute "expenditure", is thus an attribute of the category Consumer. The category Consumer is not disjoint with either Person or Corporation. In fact, every consumer must be either a person or a corporation. All of this is supported by a semantic database on the level of schema enforced integrity constraints. The relationship between categories is shown in Figure 1. Consumers can further be categorized into inherited categories G0, G1, ... G9, which represent consumers of a particular product. Thus, those consumers who are soap users will be categorized into the category "Soap Users" (one of Gi). The same consumer may be categorized into several Gis if he is a user of several types of products. In our initial database population about 50% of all objects in the database will be categorized into each of the following categories: Legal Person, Person, Consumer and several of the G0, G1, ... G9 categories. Some will be categorized into Figure 1. Relationship between subcategories Consumer Legal Person Person Corporation 4 Legal Person, Corporation, Consumer and several of the G0, G1, ... G9. Some will be just Person and Legal Person or Corporation and Legal Person. In addition to this, there will be some objects in the category Store. Consumers will be related to the stores they usually shop at. This relation is many-tomany, which means that a consumer may be related to several stores at once and a single store will, with high probability, be related to many consumers. NAME: STRING TOTAL ADDRESS: STRING TOTAL A0, A1 … A9: INTEGER C0, C1 … C9: STRING EXPENDITURE: INTEGER A0, A1…A9: INTEGER C0, C1 … A9: STRING A0, A1 … A9: INTEGER C0, C1 … C9: STRING ->KNOWS (M:M)-> NAME: STRING SSN: INTEGER HOBBY: STRING M:M ADDRESS: STRING NAME: STRING TOTAL TYPE: STRING Customer-of (m:m) … PERSON LEGAL PERSON CORPORATION CONSUMER STORE G0 G1 G9 Figure 2. Semantic Schema for the Semantic Benchmark A special relation "knows" is going from category Person into itself. The semantics of this is that a person may know and refer to us several other persons and will be related to each one of them via this relation. Since a person typically refers (and may be referred by) several other persons, this relation will also be many-tomany. A semantic schema of the database appears in Figure 2. 4. Relational Schemas for the Benchmark Database LegalPerson Id Type Name Address SSN Indexes: Name (Name) SSN (SSN) LPersonHobby LegalPersonId Hobby Indexes: Hobby (Hobby,LegalPersonId) Consumer LegalPersonId Expenditure Store Name Type ConsumerCustomerOf LegalPersonId StoreName Indexes: Store (StoreName,LegalPersonId) G0 LegalPersonId a1,a2,…,a9 c1,c2,…,c9 Indexes: a1 (a1,LegalPersonId) … a9 (a9,LegalPersonId) LPersonKnowsLPerson LegalPersonId KnowsId Indexes: Knows (LegalPersonId,KnowsId) G1 LegalPersonId a1,a2,…,a9 c1,c2,…,c9 Indexes: a1 (a1,LegalPersonId) … a9 (a9,LegalPersonId) G9 LegalPersonId a1,a2,…,a9 c1,c2,…,c9 Indexes: a1 (a1,LegalPersonId) … a9 (a9,LegalPersonId) … Figure 3. A relational schema for the Sparse model While the benchmark application has a clear and obvious representation in the semantic schema, creating a relational schema for this applications in not evident. When designing the semantic schema our only concern was the readability of the schema capturing the full semantics of the application. In designing a relational 5 schema, we have to think more about the efficiency of the queries that we expect will be executed on this database and about the tradeoffs between this efficiency, readability, and the size of the database. Among the many choices for the relational schema we considered (for detailed analysis see [13]), we have chosen two that we believe to be the best candidates for efficient implementation. We call them the Sparse model and the Compact model. The corresponding relational schemas for these two models are shown in Figures 3 and 4, respectively. In the Sparse model the creation of ten indexes per group (consisting of LegalPersonId and ai) is reasonable to facilitate efficient access to the data in G0…G9. Even though our benchmark queries do not access every ai in every Gi, the schema should accommodate all similar queries with the same efficiency, so we have to create all of the indexes. However, creating so many indexes will slow down update operations and take up too much disk space and cache memory. LegalPerson Id Type Name Address SSN Indexes: Name (Name) SSN (SSN) LPersonHobby LPId Hobby Indexes: Hobby (Hobby,LPId) Consumer LPId Expenditure Store Name Type ConsumerCustomerOf LPId StoreName Indexes: Store (StoreName,LPId) Answer Type LPId Id Value Indexes: AnswerType (Type,Id,Value) Comment LPId Type Id Value LPersonKnowsLPerson LPId KnowsId Indexes: Knows (LPId,KnowsId) Figure 4. A relational schema for the Compact model For the Compact model we create two tables, one to keep all ai attributes, the other to keep all ci attributes. Each table has the columns: LegalPersonId, group number, attribute number and the value of this attribute. The primary key will consist of LegalPersonId, group number and attribute number. For this model, we need to create just one additional index consisting of group number, attribute number and value. Lower bound Upper bound Mean Variance Name length 5 40 12 5 Address length 15 100 35 20 Comment length 5 255 30 100 Number of hobbies per consumer 0 19 0 10 Number of stores per consumer 1 19 4 10 Expenditure 1 89 20 10 Number of groups a consumer belongs to 1 10 5 4 Number of brands a consumer uses 0 9 1 1 Table 2. Normal distribution of parameters for initial database population 6 5. Initial Database Population The number of Legal Persons in the initial population defines the scalability [7] of the database. The results published in this paper were obtained on a database with 200,000 corporations and 800,000 persons. 500,000 of persons and 100,000 of corporations are consumers. The data was generated randomly according to the table of Normal Distribution (Gaussian) parameters (Table 2). The detailed definition of the initial data set can be found in [13]. A random set of Persons must be pre-chosen for transaction #4. This set consists of 0.1% of all Persons in the database. 6. Database Transactions Our benchmark consists of five transactions performed independently and sequentially. We expect efficient DBMS-specific implementations for each particular database. Transaction 1: The first transaction is simple. The task is to count the number of consumers that belong to every one of the ten product consumer groups in the database. The result is just one number: the cardinality of the intersection of groups G0...G9. The formal definition of the transaction is shown in formula (1). 􀀀9 =0 = i i R G , (1) where Gi are the groups of consumers that consume a particular product. Transaction 2: The second transaction consists of two different physical database transactions. The first one finds all consumers who use brand #1 of product #1 as their first preference among the brands of product #1, and at the same time use brand #2 of product #2 as their second preference among the brands of product #2. Such consumers form a new group in the database Gnew. This new group must be created in the database and all found consumers should be categorized into it. The formal definition of the transaction is shown in formula (2). { | [ :: ] 1} { | [ :: ] 2} 1 1 1 2 2 2 G = g ÎG g G A = g ÎG g G A = new (2) The second physical transaction should delete the newly created group from the database. The sum of execution times of both physical transactions is considered the execution time of Benchmark Transaction #2. Transaction 3: The third transaction is a complex query counting those consumers who regularly shop at store X and have hobby Y, excluding those who use brand #3 of product #3 as their third preference among the brands of product #3, and at the same time use brand #4 of product #4 as their fourth preference among the brands of product #4. The result is just one number - a count of such consumers. The formal definition of the transaction is shown in formula (3). ({ | [ :: ] 3} { | [ :: ] 4}) { | [ :: _ :: ] }) ({ | [ :: ] } 3 3 3 4 4 4 Î = Î = Î = - Î = = g G g G A g G g G A c Consumer c Consumer customer of name Y p Person p Person hobby X R (3) 7 Transaction 4: The fourth transaction can be explained by the following: For each person from a given (randomly chosen) set of 0.1% of all persons, expand the relation "knows" to relate this person to all people he has a chain of acquaintance to. Abort the transaction rather than commit. Print the length of the maximal chain from a person. The formal definition of the transaction is shown in formula (4). NewDatabase OldDatabase K = , where . . , 1.. 1 . . , . . } { . . | , , , , ,... : 1 1 1 2 < > " = - < > < > = < > Î Î $ $ Î s knows a i n a knows a + a knows p K s knows p s S p Person n a a a Person i i n n (4) Transaction 5: The fifth transaction counts the number of consumers in each one of the ten product consumer groups in the database. The result is ten numbers: the cardinality of the each of the groups G0...G9. The formal definition of the transaction is shown in formula (5). R = G ,i = 0..9 i i (5) 7. Execution of Transactions The benchmark is running in single user mode. Only one client is running the benchmark transactions at a time. Thus, we are not testing concurrency control performance by this benchmark. A DBMS is, however, allowed to use any kind of parallelism it can exploit in single user mode. The benchmark transactions are executed in two modes: hot and cold. Both "cold time" and "hot time" are collected for each transaction. Both results are included in the final result. The Cold time is the time required to perform a transaction immediately after starting the DBMS on a system with an empty cache. This is normally achieved by rebooting the system before executing each transaction. The hot time is the time required to perform a transaction immediately after performing an identical transaction without clearing any cache or restarting the DBMS. To collect the hot time we run the same transaction in a loop until the time of execution stabilizes, which typically happens on the third or fourth run. Once the execution time stabilizes we compute the arithmetic mean of the following five transactions and this is considered the final hot execution time for this transaction. 8. Results and Analysis We ran the benchmark for the Sem-ODB Semantic Object-Oriented Database Engine implemented at Florida International University's High Performance Database Research Center (HPDRC) [10]. We also ran the benchmark for one of the leading commercial relational databases. The tests were done on a dual processor Pentium II 400Mhz with 256MB total memory and 9Gb Seagate SCSI disk drive under Windows NT Server 4.0 Enterprise Edition. The version of Sem-ODB used for benchmarking did not utilize the multiprocessor architecture of the underlying hardware. We did, however, observe the relational database using both processors for parallel computations. We have run tests with different memory limitations imposed on the DBMS'es. Sem-ODB was allowed to use 16 Megabytes of memory and never actually used more than 12 Megabytes for the benchmark transactions. For the relational database, two different 8 tests were conducted. In one, the relational DBMS was allowed to use 16 Megabytes, in the other 128 Megabytes. For some transactions, the 16 Megabyte quota was enough for efficient execution, for other transactions the relational DBMS was willing to use up to 128 Megabytes for better performance. Both cold and hot times were collected for each memory limitation and for both relational schemas (sparse and compact). Thus, eight execution times were collected per transaction for the relational DBMS. This was done to make sure that we have done everything we could to allow the relational database to achieve its best performance. We observed that in some cases the sparse model was more efficient, but in other cases the compact model was faster. In order to prevent criticism on the choice of the model, we decided to include all the results in this paper. We have spent a considerable amount of time inventing different implementations and fine tuning the relational database. We tried different combinations of indexes, keys, DBMS options, and schemas in order to achieve greater performance. The semantic database on the other hand, did not require any tweaking to optimize its performance. Its performance was acceptable in the very first version. The semantic DBMS is able to capture the exact semantics of the problem domain and provide a single optimal way to represent it in a semantic schema. All the appropriate indexes are built automatically and follow from the definition of the Semantic Database. By its design, it can efficiently answer arbitrary queries without the need for an experienced person to spend time tuning it for a particular application. DBMS Model Semantic Relational Sparse Relational Compact DB Size (Mb) 406Mb 1046Mb 382Mb RAM 16Mb 16Mb 128Mb 16Mb 128Mb Cold times (seconds) Transaction 1 1.61 11.52 11.55 16.11 15.94 Transaction 2 1.13 0.53 0.56 0.34 0.36 Transaction 3 0.91 5.95 5.91 5.97 5.88 Transaction 4 55.65 55.63 43.02 55.63 43.02 Transaction 5 8.62 11.66 11.53 15.31 15.17 Hot times (seconds) Transaction 1 0.04 11.66 5.39 15.81 12.58 Transaction 2 0.07 0.28 0.28 0.09 0.09 Transaction 3 0.33 2.72 2.72 2.72 2.70 Transaction 4 0.23 35.02 2.87 35.02 2.87 Transaction 5 6.85 11.36 2.17 14.92 10.32 Table 3. The benchmark results One might think that to create enough indexes for the execution of arbitrary queries, the semantic database would have to unnecessarily use too much disk space. The results however prove this not true. In our relational implementation the sparse model contains a similar number of indexes to the semantic database but requires 2.5 times more disk space. The compact model uses about the same amount of disk space as the semantic database, but has worse performance on most transactions and is not universal in the sense that this model would not be possible at all if, for example, the attributes a0..a9 were of different types. The semantic database is outperformed by the relational on a few transactions in
How much was the Altair 8800?
The altair 8800 was sold for US$395 as a kit and US$495 as assembled.
When was the altair 8800 invented?
august 30,1975
When was the Altair 8800 made?
it was made in 1975
What Intel chip was used in the Altair?
ALTAIR 8800 was used first. Answered by Pradip, Hyderabad
What was the altair 8800 and who was the inventor?
An assassin invented by Abstergo Industries.
What city was the altair computer invented in?
The MITS Altair 8800 was designed in Albuquerque, NM. I wouldn't say it was invented!
What was the name of the first computer made by Ed Roberts?
The Altair 8800.
What computer built in 1975 was named after an episode of Star Trek?
Altair 8800
What was the main complaint about the Altair 8800 personal computer?
Noise on the unterminated backplane signals.
Which year did Bill Gates invent a computer?
Never, he dropped out from Harvard, moved to NM, and wrote Altair BASIC for the MITS Altair 8800 kit.
Who were the 2 men who invented the 8080 microprocessor based Altair in 1975?
The two men that designed the MITS Altair 8800 computer kit in 1975 were Ed Roberts and Forrest M. Mims III. The Altair 8800 used the Intel 8080 as it CPU. Roberts and Forrest did not invent the 8080 - Intel did - they simply used the 8080 in their product.
What was the first home computer ever made?
The first personal home computer was the Altair 8800 which was produced in 1975 by Ed Roberts. The Altair 8800 could run thousands of CP/M software titles and also allow the user to play games such as Colossal Cave Adventure, Pong, Star Trek, and Zork. A user could also use the Altair 8800 to create spreadsheets, databases, and word processing documents.
