0
Database Design
Database design is the process of creating a detailed data model of a database. It is the next step after requirement gathering and before coding begins. A good database design can save a lot of time during the database development.
1,295 Questions
Advantages of relational database management system?
- Data Structure
The table format is simple and easy for database users to understand and use. RDBMSs provide data access using a natural structure and organization of the data. Database queries can search any column for matching entries.
- Multi-User Access
RDBMSs allow multiple database users to access a database simultaneously. Built-in locking and transactions management functionality allow users to access data as it is being changed, prevents collisions between two users updating the data, and keeps users from accessing partially updated records.
- Privileges
Authorization and privilege control features in an RDBMS allow the database administrator to restrict access to authorized users, and grant privileges to individual users based on the types of database tasks they need to perform. Authorization can be defined based on the remote client IP address in combination with user authorization, restricting access to specific external computer systems.
- Network Access
RDBMSs provide access to the database through a server daemon, a specialized software program that listens for requests on a network, and allows database clients to connect to and use the database. Users do not need to be able to log in to the physical computer system to use the database, providing convenience for the users and a layer of security for the database. Network access allows developers to build desktop tools and Web applications to interact with databases.
- Speed
The relational database model is not the fastest data structure. RDBMS advantages, such as simplicity, make the slower speed a fair trade-off. Optimizations built into an RDBMS, and the design of the databases, enhance performance, allowing RDBMSs to perform more than fast enough for most applications and data sets. Improvements in technology, increasing processor speeds and decreasing memory and storage costs allow systems administrators to build incredibly fast systems that can overcome any database performance shortcomings.
- Maintenance
RDBMSs feature maintenance utilities that provide database administrators with tools to easily maintain, test, repair and back up the databases housed in the system. Many of the functions can be automated using built-in automation in the RDBMS, or automation tools available on the operating system.
- Language
RDBMSs support a generic language called "Structured Query Language" (SQL). The SQL syntax is simple, and the language uses standard English language keywords and phrasing, making it fairly intuitive and easy to learn. Many RDBMSs add non-SQL, database-specific keywords, functions and features to the SQL language.
The database catalog of a database instance consists of metadata in which definitions of database objects such as base tables, views (virtual tables), synonym, value ranges, indexes, users, and user groups are stored.
The SQL standard specifies a uniform means to access the catalog, called the INFORMATION_SCHEMA, but not all database follow this, even if they implement other aspects of the SQL standard. For an example of database-specific metadata access methods, see Oracle metadata.
Trigger is a statement that is automatically executed by the system as a side effect of a modification to the database. Several existing systems have their own non standard trigger functions. For a trigger we need to specify the condition under which the trigger is executed.
What are the qualities you think this job requires?
The ability to ask a well-specified question, perhaps.
Database approach VS traditional approach?
Database Approach vs. Traditional File Processing
- Self contained nature of database systems (database contains both data and meta-data).
- Data Independence: application programs and queries are independent of how data is actually stored.
- Data sharing.
- Controlling redundancies and inconsistencies.
- Secure access to database; Restricting unauthorized access.
- Enforcing Integrity Constraints.
- Backup and Recovery from system crashes.
- Support for multiple-users and concurrent access.
How many types of database models are there?
HOW MANY TYPES OF DATABASES IN COMPUTERS PLS GIVE ME LIST OF IT. 4
We know a database is one that stores data related to each other. A network database is just like network database only difference between them is, in network database records are connected by means of a link.
What is normalization in DBMS?
Normalisation means make table very effective and usable means make table atomic ,unique primary key,not redundancy etc.
What are the advantages of database system?
these are some of the advantages of database management systems
1.allows remote login.
2.eases the problem for mobility because of number1(remote login)
3.allows sharing of research and other works.eg like we are doing now(sharing)
3.makes it for the database administrator to monitor user activities.
4.provides necessary security to protect the data stored.eg data encryption.
5. e.t.c
Characteristics of Good Quality Data?
1. accurate information
2. organized information
3. timely information
4. verifiable information
5. accessible information
6. economical information
7. useful information
List the advantage and disadvantage of database management system?
Answering "List the advantage and disadvantage of object oriented database model?" Answering "List the advantage and disadvantage of object oriented database model?"
What would you use a database for?
collecting data, about someone, something etc
For example a company may have a data base of all their clients addresses.
What is the basic difference between RDBMS and DBMS?
DBMS acronym for Database management system. There are number of DBMS like RDBMS, ORDBMS, HRDBMS etc . RDBMS is basically to define relationship between the tales and also it follows various codds rules.
What are the different types of databases?
There are presently two types. (A) Analytic Databases - read only and used to store archived data for analysis work and (B) Operational Databases - Operational databases - Theseallow you to modify the data (add, change or delete data).
These types of databases are usually used to track real-time information. For example, a company might have an operational database used to track warehouse/stock quantities.
Example er diagram for hospital?
how to draw e-r diagram for hospital management system plz show the figure?
What are the advantages and disadvantages of online booking?
adv to company:
less staff needed
no physical space - no bills, no rent of office
attracto more costumers as internet used by many people
disadv to cmpany:
less personal touch - harder to sell
fraud - company loses money
initial costs - hardware, setting/maintaining webpage
adv to costumer
don't neet to leave home- people with disabilities find it easier
24/7
quicker than discussing with travel agent
no risk of doble booking
look at different companies and chose cheapest
disadv to costumer
intert access and computer skills
hacker may intercept data - steal money
if dial internet - phone line increases and cant receive phone calls or make any
advantages:
Advantages cheaper flights than travel agents on the high street
You can compare the prices
You can read reviews from other customers who have stayed at the hotel
you don't need to leave the house
there is 24 hour service
disadvantages:
No one to ask there advice on the holiday like in a travel agents
credit card/ identity theft
mistakes can be made when filling in the booking form
site may not be secure
What is the meaning of input process output?
An Input is simply means a entrance or change made into a system and can eb used as modellign leading on to the process.
The process is a type of engineering that is used to complete a project as a WHOLE!
whereas an output is an exit froma system after conclusion and the finish completing the project and showing it.
An individual trained in the design and building of databases is called a database?
A database designer or database administrator.
In what ways can a computer process data?
The part of the computer that processes data is called the processor or processing unit. Older computers had a Central Processing Unit (CPU) . Modern machines often have more than one processing unit. The processor fetches and decodes the instructions that make up the program as well as doing the arithmetical operations.
A default value is the one that has been considered the most appropriate on several
systems, methods, programs. Obviously it is the parameter which works better, otherwise it wouldn't be set as a standard value. To set something "by default" is the same as to choose a value, a configuration more convenient for that purpose.
// macros for simplicity
#define MAX(x,y) (x>y?x:y)
#define MIN(x,y) (x<y?x:y)
/*
** drawLine
**
** Draw a line from vertex (x0,y0) to vertex (x1,y1) using
** the midpoint line algorithm, implemented using OpenGL.
**
*/
void drawLine( GLint x0, GLint y0, GLint x1, GLint y1 ) {GLint dE, dNE, x, y, d, dx, dy;
// check if we need to switch the points
if( x0 > x1 ) {
x0 = x0 + x1;
x1 = x0 - x1;
x0 = x0 - x1;
y0 = y0 + y1;
y1 = y0 - y1;
y0 = y0 - y1;}
// calculate deltas
dy = y1 - y0; dx = x1 - x0;
// special cases
if( dx -1 - diag down-right
glBegin(GL_POINTS);
for( x = x0, y = y0; x <= x1; x++, y-- ) {
glVertex2i(x,y);}
glEnd();}else { // general cases
// midpoint algorithm
if( abs(dy) < dx ) { // small slope
dE = 2 * abs(dy);
dNE = 2 * (abs(dy) - dx);
d = dE - dx;
glBegin(GL_POINTS);
for( x = x0, y = y0; x <= x1; x++ ) {
glVertex2i(x,y);
if( d <= 0 ) {
d+= dE;}else {
y += (dy>0?1:-1);
d += dNE;}}// for x = x0 to x1
glEnd();}else { // large slope
dE = 2 * dx;
dNE = 2 * (dx - abs(dy));
d = dE - abs(dy);
glBegin(GL_POINTS);
for( x = x0, y = y0; (y0 < y1 && y <= y1)
(y0 > y1 && y >= y1); y+=(y0 < y1?1:-1) ) {
glVertex2i(x,y);
if( d <= 0) { x ++;
d+= dE; }else { d += dNE; }}// for y = y0 to y1
glEnd();}}
}// drawLine()
Disadvantage of optical fiber communication?
•Only economical when the bandwidth is fully utilised
•High cost of installation
•A lot of hardware at the moment is not compatible with fibre optic cables, they need to be adapted in order to make use of them
