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Database Programming
Databases are collections of tables that maintain and display information, often collaboratively; this information can be used for interaction with an application or gaining general knowledge. Questions about database engines and modifying or using them belong in this category.
8,803 Questions
Data processing concepts and techniques?
The process of collecting, storing, and recovering some information to produce a set of outputs is called Data processing. Data processing software incorporates data management, different methods of data processing software package, writing process for several programming languages, and file and database systems.
What is the difference between sql and pl-sql?
- Platform dependency-
The primary difference is with respect to platform dependency, SQL is basically limited to the Windows platform where as Oracle is operable on multiple platforms such as Windows, UNIX and Linux etc. This multi-platform compatibility of Oracle makes it a universal enterprise solution, which makes it mandatory for the Oracle DBA to be acquainted with the different platforms where as the Sql DBA just needs to be familiar with the windows platform..
- Clustering technology-
Oracle is significantly ahead of its opponent when it comes to clustering technology, Oracle makes use of RAC technology which enables two instances to act on the same data in active-active configurations.
- Locking and concurrency -
Oracle had a multi-version consistency model which means that "readers don't block writers and writers don't block readers." Sql on the other hand has a very simple locking mechanism which follows the rule that "writers block readers and readers block writers."
- File system-
Oracle includes IFS (Internet File System), Java integration, SQL is more of a pure database.
- Replication -
SQL Server provides a far more simple and flexible system for replication and synchronizing of data when compared to Oracle, it involves a set of technologies for copying and distributing data and database objects from one database to another and then synchronizing between databases to maintain consistency.
- Administration-
SQL server GUI is simple and easy to work with where as the Oracle server is not very user friendly as most of it command line is based.
by....... Sankar
Generally port 21 is for FTP
22 for FTP using SSH
990 FTP using SSL
What is need for normalization in dbms?
DBMS stand for data base management system
We normally use dbms systems to improve the management of the data and accesss of the data too.
well if the data is in normal form it is very easy to access it as well as manage it for the system.
In the process of normalization we increase the normality of the data by removing the dependencies redundancy applying the entity integrity and referential integrity.
there are many stages of Normalization process..:
1. 1NF
2. 2NF
3. 3NF
4. BC NF
5. 5NF...etc..
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Addendum:
While the above answer is not incorrect, I don't believe it properly answers the question in a way that anyone who is not already a database expert would understand. The question is this: Why do we need to normalize data in a database. Here is the answer:
First, in order to answer this you have to understand what normalization is. Normalization is the process of removing duplicate information and dependent information from a database.
Lets say for example you have two tables, one called 'employees' and another called 'addresses'. In the employees table you include a field called 'city' and you also include this field in the addresses table. The reason you might do something like this is that you want to be able to get a basic idea of where your employee lives without having to look up the address so you include it in both locations.
Why is this bad? well it should be obvious but here it is. Its bad because it allows for inaccuracies. What if the employee moves and changes his address and you forget to change the city listed in the employees table (or your system crashes while you trying to do it)
the proper way to do this would be to not have the 'city' field in the employee table and instead have a reference to the address table. When querying this info you need to join the two tables and this will ensure that you always have the correct info.
-Dallas Caley
KB = kilobyte , while MB = megabyte
kilobytes are smaller than megabytes.
1 kilobyte = 1,024 bytes
1 megabyte = 1,048,576 bytes
Three main types of database applications and briefly explain them with suitable example?
A collection of programs that enables you to store, modify, and extract information from a database. There are many different types of DBMSs, ranging from small systems that run on personal computers to huge systems that run on mainframes. The following are examples of database applications:
- computerized library systems
- automated teller machines
- flight reservation systems
- computerized parts inventory systems
From a technical standpoint, DBMSs can differ widely. The terms relational, network, flat, and hierarchical all refer to the way a DBMS organizes information internally. The internal organization can affect how quickly and flexibly you can extract information.
What is advantages and disadvantages of Distributed System?
Cluster systems are ultimately a brilliant discovery to the world of programming. The advantages are network unity, and the capability of managing work from different locations. They are cost effective, they are flexible. The disadvantage is all computers connected are easily effected by one malfunction. Since there is data sharing involved, it may make it easier to breech security efforts from one information system to the other.
Database as the name suggest is the collection of records or data that are related to each other. There are mainly three type of database network database, object oriented database and hierarchical database. Database helps in maintaining data consistency and data integrity.
What is the difference between an online database and a website?
A website is a document that is sent over the internet for people to view with an internet browser (Like internet explorer). An example is this yahoo answers page you are looking at right now. Almost anything you go to with internet explorer is a website (also called a webpage).
A database is a collection of records that are stored on a computer. For example, if I used Microsoft Access to make a table that lists all the books I have. A database can be viewed over the internet through a website.
For a better understanding, view the two sources below.
Source(s):http://en.wikipedia.org/wiki/Databasehttp://en.wikipedia.org/wiki/Website
Difference between right join and inner join?
Hi,
Natural Join: It is combination or combined result of all the columns in the two tables.
It will return all rows of the first table with respect to the second table.
Inner Join: This join will work unless if any of the column name shall besxame in two tables
Two disadvantages of a computerised database?
the first one they can sometimes not save your work and second they breake down
Burst time is an assumption of how long a process requires the CPU between I/O waits.It can not be predicted exactly, before a process starts.
It means the amount of time a process uses the CPU for a single time. (A process can use the CPU several times before complete the job)
What is another name for voltage?
Voltage can also be called "potential" and is measured across components or sections of a circuit.
Answer'Voltage' is another word for 'potential difference', not'potential'!
What are the advantages and disadvantages of network analysis?
Advantages are that you will know where everything is and when things will be done. Disadvantages are they are difficult to make.
What is the difference between DBMS and Data warehouse?
A database is used to record, retrieve, update business transactions which are occured daily in business life. A data warehouse is used to record historical data, purely for analysis purpose for top management.
What is the difference between DBMS and a database?
The database holds the records, fields, cells ..with data. The DBMS is the "tools" used to manipulate the data in the database. An example of a DBMS is SQL Server.
The DBMS is the database engine itself. This is the core, the actual program that contains the logic to execute your SQL statements. performs that actual data access based upon these commands (relationaly).
whereas DS is linked with improving the speed of traversing and searching the data in main memory.
As we all know that the processor can only process the data that is available in main memory. Therefore the different models used to organize data in main memory are collectively referred as DS.
How many bytes in 8 gigabytes?
1 gigabyte = 1,073,741,824 bytes
so....
1,073,741,824 times 4 = 4,294,967,296
4 gigabyte =4,294,967,296
What is the difference between record management and information management?
A main difference is that records management is associated with governance, risk, and compliance. Information management is the collection and management of information from one or more sources and the distribution of it to various audiences.
What are the advantages and disadvantages of face recognition system?
A facial recognition system is a computer application or device that can identify individuals based on their unique facial characteristics. Unlike many other identification methods (e.g., fingerprints, voiceprint, signature), they do not need to make direct contact with an individual in order to verify their identity. This can be advantageous in clean environments, for surveillance or tracking, and in automation systems.
Because the system keeps a reference model of the individual, and captures their image for identification, there may be concerns about how the system is perceived by its users. They may also be more error-prone when identifying individuals, due to the fairly recent development of the technology. In addition, if used for security purposes, it is considerably more expensive and complex than other methods, such as mechanical locks, passwords, or identification cards.
Application of queue in data structure?
Application of stack:
- It is used in various expression conversion and evaluation - infix to post-fix or prefix evaluation.
- Stack is implicitly used by system while calling to sub routines function from main program.
- Recursion
Application of queue:
- Used by operating system in scheduling jobs and spooling (queue of print jobs)
- Disk I/O calls
- Queue is also part of the architecture of processors ex- 80386,8086
What is the difference between uart and usart?
UART is universal asynchronous receiver/transmitter. It is a piece of computer hardware that translates data between parallel and serial forms. Modern ICs that have UART's that can also communicate synchronously are called USARTs (universal synchronous/asynchronous receiver/transmitter).
In software engineering, an Entity - Relationship model(ER model for short) is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements in a top-down fashion. Diagrams created by this process are called entity-relationship diagrams or ER diagrams.
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What are the advantages of using database system instead of file system?
1. Redundency of data means some information may be duplicated in several places in file processing s/y .this can also be refined through DBMS.
2. Accessing of data is difficult in file processing s/y .to access the different data
we requried different program many times in other word for different type application requried different application program .
3. Multiple user can access the same data in DBMS.
4.Security also provided by DBA(Database adminstraror).
