Sunday, August 16, 2009

My_Idea_Is

A. Disscuss what you have leaned and understood out RDBMS is, so for


A relational database management system (RDBMS) is a program that lets you create, update, and administer a relational database.

A short definition of an RDBMS maybe a DBMS in which data is stored in the form of tables and the relationship among the data is also stored in the form of tables.


B. Define how each of he following fit and function within the famework of RDBMS systems:


1. Ket Fields - A field in a recod that holds unique data which identifies tht record from all e other records in the file or database. Account number, product code nd customer are typical key fields.

2. Database Records - A database record consists of one set of tuples for a given relational table. In a rational database, records correspond to rows in each table.


3. Data Queries - A database qury describes instructions sent to the database in SQL that request some kind of function to be performed on your data set or database.


4. Data Types - Data type is a data storage format that can contain a specific type or range of values.


5. Data Forms - A data is a fancy phrase for a dialog box with the fields for one record. The form sits on top of your excel spreadsheet and allows you o enter up to 32 fields per record.

6. Tables/ database files - In relational darabases and flat file databases, a table is a set of data elements that is organized using a model of vertcal columns and horizontal rows. A table has speified number of columns, but ca have any number of rows


Database Tables - Database tables consist of columns and rows. Each columns contain a different type of attribute and each row corresponds to a single record.


7. Relationships (Table Linkage) - Relational database offer powerful methods fo the efficient organization, storage, maintenance, integration, processing and interrogation of large, omplex data sets. These properties arise fundamentally from two types of logical constucts that are central to the structure and function of relational database systems: tables and the relationships that connect them.

Sunday, July 5, 2009

MY_ASSIGNMNT

DATA TYPES

A. What are they?

B. What role do they play in a database?



C. Enumerate the datat types. Give the discription of each. 3 DBMS software

Data type Description
# (symbol) A self-contained unit that can be used to represent a condition or flag. For example, #list or #word.
Array (JavaScript syntax only) Although not literally a data type, an Array object can be used to work with linear lists of values. The functionality of an Array object is similar to that of the List data type in Lingo.
Boolean A value that is TRUE (1) or FALSE (0). In Lingo, all TRUE or FALSE values are simple integer constants, 1 for TRUE, 0 for FALSE. In JavaScript syntax, all true or false values are by default the actual Boolean true or false values, but are converted to simple integer constants automatically when required in Director.
In Lingo, TRUE and FALSE can be either lowercase or uppercase. In JavaScript syntax, true and false must always be lowercase.
Color Represents an object's color.
Constant A piece of data whose value does not change.
Date Although not literally a data type, in JavaScript syntax a Date object can be used to work with dates. In Lingo, use the date() method to create a Date object and work with dates.
Float (Lingo only) A floating-point number. For example, 2.345 or 45.43.
Function (JavaScript syntax only) Although not literally a data type, a Function object can be used to specify a string of code to run.
Integer (Lingo only) A whole number. For example, 5 or 298.
List A linear or property list made up of values or property names and values, respectively.
Math (JavaScript syntax only) Although not literally a data type, a Math object can be used to perform mathematical functions.
null (JavaScript syntax only) Denotes a variable whose value behaves as 0 in numeric contexts and as FALSE in Boolean contexts.
Number (JavaScript syntax only) Although not literally a data type, a Number object can be used to represent numerical constants, such as a maximum value, not-a-number (NaN), and infinity.
Object Although not literally a data type, an Object object can be used to create a custom named container that contains data and methods that act on that data.
Point A point on the Stage that has both a horizontal and vertical coordinate.
Rect A rectangle on the Stage.
RegExp (JavaScript only) A regular expression pattern that is used to match character combinations in strings.
String A contiguous sequence of keyboard symbols or character values. For example, "Director" or "$5.00".
undefined (JavaScript syntax only) Denotes a variable that does not have a value.
Vector A point in 3D space.
VOID (Lingo only) Denotes an empty value.

Example DBMS software
Oracle
Filemaker
MySQL

Sunday, June 28, 2009

MV versus Data Field

Memory Variable

Variables are explicitly named memory vocations variables, the free pascal compile generates machine code to move the vaalue to the memory location reserved for these variables.

A memory variable is the name for a place in the computer's memory where you store some data.


Variable types:

In modern programming languages, variables are declared to be of a type.
Apart from numbers, the CPU does not make any kind of distinction about the data in its memory. It treats it as a collection of bytes. Modern CPUs (apart from those in mobile phones) can usually handle both integer and floating point arithmetic in hardware. The compiler has to generate different machine code instructions for each type, so knowing what the type of variable helps it generate optimal code.

What Types of Data Can a Variable Hold?: The fundamental types are these four.
· Integers (both signed and unsigned) 1,2,4 or 8 bytes in size. Usually referred to as ints.
· Floating Point Numbers up to 8 bytes in size.
· Bytes. These are organised in 4s or 8s (32 or 64 bits) and read in and out of the CPU's registers.
· Text strings, up to billions of bytes in size. CPUs have special instructions for searching through large blocks of bytes in memory. This is very handy for text operations.
Example of Data Types:
· Arrays of types- single dimension like drawers in a cabinet, two dimensional like post office sorting boxes or three dimensional like a pile of beer crates. There can be any number of dimensions, up to the limits of the compiler.
· Enums which are a restricted subset of integers.
· See What is an Enum?
· Structs are a composite variable where several variables are lumped together in one big variable.
· Streams provide a way to manage files. They're a form of string.
· Objects. Like structs but with much more sophisticated data handling.

Data Field

-An area in the main memory of the computer in which a data record is contained.

In the structure of a database, the smallest component under which data is entered through data capture or data entry. All data fields in the same database have unique names, several data fields make up a data record, several data records make up a data file, and several data files make up a database.

Tuesday, June 23, 2009

ITS 121 - Storage

Juliet B. Catubig

1.) Differentiate Information versus Data

Information-When data are processed, organized, structured or presented in a given context so as to make

them useful, they are called Information.


Data-Data is raw material & unorganized facts that need to be processed.


2.) Differentiate Data storage versus Computer Storage


Data Storage - Anything with information recorded on it.

2 main categories: Primary data storage & Secondary data storage


Computer Storage - an electronic memory device

- a device or portion of device that is capable of receiving data, retaining them for

an indefinite time, and supplying them on command.


3.) Differentiate Operating System versus Computer System


Operating System - is a software program that enables the computer hardware to ommunicate and operate with the computer software.

- Software designed to control the hardware of a specific data-processing system in order

to allow users and application programs to make use of it.

Computer System - A complete working computer. The computer system includes not only the computer, but

also any software and peripheral devices that are necessary to make the computer

function. A set of connected computer equipment, devices and software.