Tag Archives: Database
Data Dictionary
A data dictionary contains a set of precise and accurate definitions of all DFDs, data elements and data structures. The following rules are followed in constructing a data dictionary: a) The terms used to describe data structures are always in … Continue reading
Data Couple and Control Couple
Data couple carries data between two modules and it can have upward or downward direction. Data flows are depicted using named arrows with a small circle at one end. But control couple only carries information about data couple and does … Continue reading
How to Change Password in Oracle ?
You can change your Oracle login password using the Change Password page. Changing your password regularly reduces the risk of someone obtaining your password and gaining unauthorized access to your account. You must specify your username, old password, and your … Continue reading
Script Formatting and System Variables in Oracle
Executing a script and formatting its output are controlled by system variables. A system variable in iSQL*Plus is similar to a variable in any programming language. Like a column in a row of a table, a system variable can hold … Continue reading
NULLs: What, When, Why, and How ?
NULL value in an Oracle table is nothing. A NULL is neither zero, a blank character, or an empty string. NULLs can be the source of much consternation when a query is not returning the expected results. NULL :- A … Continue reading
The DUAL Table in Oracle
Because Oracle SQL is table-centric, most operations performed with SQL must reference some kind of table or view. For example, consider the following SQL statement: SELECT NAME; SELECT NAME * ERROR at line 1: ORA-00923: … Continue reading
DATA MINING FOR FINANCIAL DATA ANALYSIS
Most banks and financial institutions offer a wide variety of banking services (for example saving balance checking, individual transactions), credit (such as loans, mortgage) and investment services (mutual funds). Some also offer insurance services and stock investment services. Financial data … Continue reading
CLUSTERING IN DATA MINING
Clustering is a division of data into groups of similar objects. Each group, called cluster, consists of objects that are similar between themselves and dissimilar to objects of other groups. Representing data by fewer clusters necessarily loses certain fine details … Continue reading
ROLLUP and CUBE Operators in Oracle
Sometimes, a simple GROUP BY clause just isn’t enough in a query. Once you generate a report of, let’s say, average salary by department or the standard deviation of sick days by job title, you often must run a second … Continue reading
APPLICATIONS OF DATA MINING
Data mining has many and varied fields of application some of which are listed below. Retail/Marketing 1. Identify buying patterns from customers 2. Find associations among customer demographic characteristics 3. Predict response to mailing campaigns 4. Markets analysis Banking 1. … Continue reading
REASONS FOR THE GROWING POPULARITY OF DATA MINING
1.Growing Data Volume The main reason for necessity of automated computer systems for intelligent data analysis is the enormous volume of existing and newly appearing data that require processing. The amount of data accumulated each day by various business, scientific,and … Continue reading
HOW DO WE CATEGORIZE DATA MINING SYSTEMS?
There are many data mining systems available or being developed. Some are specialized systems dedicated to a given data source or are confined to limited data mining functionalities, other are more versatile and comprehensive. 1. Classification according to the type … Continue reading
WHAT CAN DATA MINING DO?
The kinds of patterns that can be discovered depend upon the data mining tasks employed. By and large, there are two types of data mining tasks: descriptive data mining tasks that describe the general properties of the existing data, and … Continue reading
WHAT KIND OF DATA CAN BE MINED?
In principle, data mining is not specific to one type of media or data. Data mining should be applicable to any kind of information respiratory. However, algorithms and approaches may differ when applied to different types of data. Indeed, the … Continue reading
Database Management System
A database management system (DBMS) is a collection of interrelated data and a set of programs to access the data. The collection of data, usually referred to as the database, contains information related to an enterprise. The primary goal of … Continue reading