SQL Database Design For Developers at php[tek] 2024
Lecture 2 it fundamentals
1. LECTURE 2 – IT FUNDAMENTALS
Electronic Data Processing
ElectronicDataProcessing (EDP) – the processing of data through the use of computers
DataProcessing– the manipulating of data into a more useful form. It is the modern name
for paperwork and involves the collecting, processing, and distributing of facts and figures
to achieve a desired result.
Data Processing Cycle
Input – in this stage the initial data, or input data, are prepared in some convenient form for
processing.
Processing – in this step the input data are charged, and usually combined with other
information, to produce data into more useful form.
Output – here the results of the preceding processing steps are collected.
Classification of Data Processing
BusinessDataProcessing – characterized by the need to establish, retain, and process files
of data for producing useful information. Generally, it involves a large volume of input data,
limited arithmetical operations, and a relatively large volume of output.
Scientific Data Processing – involves a limited volume of input and many logical or
arithmetic calculations. Unlike business problems, most of the scientific problems are non-
repetitive, requiring a “one-time” solution.
Data Processing Operations
Recording – refers to the transfer on data into some form or document. It relates to the
documentation of intermediate figures and facts resulting from calculations.
Verifying – refers to the careful checking of the recorded data for any errors.
Duplicating – refers to the reproduction of the data into many forms or document.
Classifying – refers to identifying and arranging items with likes characteristics into groups
or classes.
Sorting – refers to arranging or rearranging data in a predetermined sequence to facilitate
processing. Sorting is done in alphabetic or a numeric order.
Calculating – refers to arithmetic manipulation of the data.
2. SummarizingorReporting – it is here where a collection of data is condensed and certain
conclusions from the data are represented in a meaningful format that is clear, concise and
effective.
Merging – this operation takes two or more sets of data, all sets having been sorted by the
same key, and puts them together to form a single sorted set of data.
Storing – refers to placing similar data into files for future reference.
Retrieving – refers to recovering stored data and/or information when needed.
Feedback – refers to the comparison of the output(s) and the goal set in advance, any
discrepancy is analyzed, corrected, and fed back to proper stage in the processing
operation.
Methods of Processing Data
BatchProcessing – a technique in which data to be processed are collected into groups to
permit convenient, efficient, and serial processing.
On-lineProcessing – a technique that uses devices directly connected to the CPU either for
entry or inquiry purposes.
Real-timeProcessing – a method which has the capability of a fast response to obtain data
form an activity or a physical process.
DistributedProcessing – it generally consists of remote terminals linked to a large central
computer system to help the user conduct inquiries about accounts, process jobs, or other
data processing operations.
Elements of an EDP System
I. Hardware – the physical equipment that make up a computer system. It includes its peripheral s
and components.
Examples: Monitor, CPU, Keyboard, Mouse, Speaker
CentralProcessingUnit (CPU) – heart and brain of the computer system. It is where data
processing takes place.
Parts of CPU
MainMemory (Primary Storage) – data and instructions are stored here. Sometimes known
as the ‘internal’ memory of the computer.
ArithmeticLogicUnit (ALU) – accomplishes the arithmetical and logical operations.
Accumulator – a kind of holding area which retains answers that are produce by
adders.
3. Adders – add the bits coming from the memory and produces a 1 or 0 depending
upon the components of the received bits (contraction for binary digit).
Control Unit – supervises all the activities based on a set of instructions programs stored in
the main memory. It selects, interprets and executes the instructions.
Registers – functions as temporary storage devices during process of computation.
Input/Output Devices
InputDevices – physical equipment which reads or translates data consisting of alphabets,
numbers, or symbols into a form that can be understand by the computer.
Example of Input Devices: keyboard, mouse, scanner, joystick, graphics pad, bar
code reader
OutputDevices – physical equipments which translate the outcome of the computations
and related activities carried out in the CPU. Its objective is to convert data and information
onto a form, such as a printed report or visual display that can be understood by humans.
Example of Output Devices: monitor, printer, plotter, desktop speaker
Types of Computer Memory
InternalMemory – contained in the silicon chip and can hold instructions and data which
the computer is currently working on or information which the CPU needs to work very
rapidly because the speed of the CPU is very high and acquires information to be readily
available.
RandomAccessMemory (RAM) – stores instructions which later can be erased or
changed. All information stored here are lost and erased when computer is turned
off.
ReadOnlyMemory(ROM) – contains permanently stored instructions that a
computer is required to keep able to perform its basic routine operations. Part of
CPU.
ExternalMemory – uses tapes and disk to store information. External memory is physically
separated from CPU.
Examples: diskette, compact disk, tape backup, hard disk
II. Software – the tangible element composed of programs that instruct the computer what to do.
Examples: DOS Operating System, Windows 98, MS Office, Cartoon Manila, etc.
Types of Software
4. I. SystemsSoftware – the programs or instructions which direct the internal operations of the
computer. Also called operating software and are normally contained in a disk pack or floppy
diskette or already embedded on a chip.
Classification of System Software
A. OperatingSystem – most important type. It is a group of related programs that
supervises or monitors the execution of an application program and provides services
such as language translation, input/output control, and job scheduling.
B. LanguageTranslators – programs which convert human readable form into a series of
binary pattern of zeroes and ones.
LowLevelLanguage – Machine Language, Assembly Language difficult to learn,
coding was tedious, and difficult to correct and find error in programs.
HighLevelLanguage – COBOL, BASIC, FORTRAN, RPG or PASCAL
C. UtilityorServicePrograms – use for specialized data process problems.
II. ApplicationSoftware – Provides a solution to a specific business, scientific, engineering or
research problems, or which perform specific operations or applications. Used to predict
weather conditions, to keep track of an organization’s inventories, can assist an individual in
balancing his checkbook, or game program for entertainment (e.g. Pac-man).
Types of Application Software
Customized – a program developed to solve a specific problem peculiar to a particular
company or user.
Packaged – Pre-written programs for common applications that can be used by a
number of users with little or no changes.
Examples:
Formicrocomputers (Personal Computer) – word processing, spreadsheet analysis and
database management system.
WordProcessing (e.g. MS Word) – a text editing program which allows the user to type,
compose and correct manuscripts without the need to retype when errors or changes on
such manuscript are made.
Spreadsheet (e.g. Excel) – allows the user to do “what if problems”. These are powerful;
business tools for budget reporting, financial projections and cost estimating.
Database (e.g. Access) – allows the user to create and store information based on his own
requirements. Also called “electronic filing”.
5. III. Peopleware – this refers to the people who work with the computer so that it can be used to
find solutions to problems. Also, these refer to persons who used the information generated by the
computer.
SystemAnalyst – primarily responsible for the analysis, design, development and
implementation of systems for such applications as payroll, inventory control, accounts
receivable, and sales analysis.
DatabaseAdministrator – designs, creates, and maintains the organization’s database.
DataCommunicationSpecialist – designs and maintains computer networks that link
computers and terminals for data communications.
ComputerProgrammers – write programs or perform programming.
Applicationprogrammers – translate specifications given by system analyst and
prepare programs for applications.
SystemProgrammers – develop and maintain system software.
OperationsPersonnel
Dataencoder – responsible for transferring data from the source document (e.g.
Time cards) into a form which the computer can understand.
Datacontrollers – verify and check whether the data prepared are accurate and
complete.
Computeroperators – actually handle the machine; responsible to load and unload
the programs, mount the data tapes, disks, or cards; prepare to receive the output
data from printer.
Librarian – a person who catalog, monitor, and control the distribution of disks,
tapes, system documentation, and computer-related literature.
Computer Instructor – conducts the training sessions.
Preventive Maintenance for Computers
Do not place a PC directly near a heating or cooling source, such as heating vents or air
conditioners. Both excessive heat and cold can damage a PC
Do not connect power sources directly into wall outlets but rather connect them first to
some form of surge protector. Surge protector prevents electrical surges from destroying
hard drives and erasing data
Accumulation of dust can seriously hamper a PC’s ability to cool down, and even if you
never open your computer’s case, duct can still get in through the drive openings.
6. Be careful when moving PC from one location to another. Even small jolts can dislodge chips
and expansion board.
Keep the root directory organized. Only keep your system’s start up and software
initialization files in the root directory.
Do not store data files in the same directory that your store your software. This will
eliminate the possibility of accidentally erasing or overwriting a software file.
Keep a set of rescue disk for the operating system.
Keep a backup copy of original software, either CD of floppy disk. This type of software
copying perfectly legal.
Keep meticulous records of default settings, any changes you make in the system’s CMOS
setup that differ from the default settings, and any maintenance you perform in the system.
Keep records of any expansion cards you install and the procedures you follow to install
them.
Save all documentation that comes with your PC and its components. You may need to refer
to the documentation if something goes wrong.
Do not compress your hard drive. Compressed hard drives are more likely to become
corrupted than those that have not been compressed.
Keep backup copies of any important data on removable medium. Hard drives can fail and
having important data on more than one medium can save a lot of stress and headaches.
Install a virus scan program that automatically scans for viruses when the system boots. Do
not download any files from the internet unless you are certain that the source is not
transmitting a virus to you.