Thursday, 29 March 2012

Basics of Database

What is database?
Ans: Database is a storage space of related data for processing.Here we can store in tables or related schema.

What is data? 
Ans: Data is a group of measures and descriptive information of an object.

What is information?
Ans: Information is a data related to a single subject.

What is table?
Ans: Table is  a set of data elements arranged in rows and columns.Data is arranged in rows and the description will be arranged in columns.

What is metadata?
Ans: Metadata is data about data.Means column is metadata in database because column name describes the data  in the column-wise rows.


Sunday, 25 March 2012

Why we Maintain Data ?


Why we use Database ?
Ans: Database is a storage space for everything. We can store the data in tables. In organizations, generally for records maintenance. We can store the historical data as well as present data. If the data size is increased, the past data may lost .We can maintain the transaction data in data base.
Why we use Datawarehouse?
Ans: Data ware house is also a storage space like database. The data ware house is a huge database than a normal database. Database is a part of data ware house. We can analyse the data from the data ware house easily because we have a huge data i.e., Historical data. Based on some conditions the data will be loaded from database to data ware house. Generation of a report is very easy from data ware house for data analysis.
Why we use Reporting?
Ans: Reporting is a process of generation of reports. In real-time,the higher management need to know the present status of the organization. So reports are very useful to analyse the data and for decision making or forecasting .

Friday, 23 March 2012

SQL Questions


1. What is SQL?
Ans: Structured Query Language(SQL) is a programming language for implementing the database queries. SQL was first developed by IBM.

2. What is PL/SQL?
Ans: Programming Language/Structured Query Language(PL/SQL) is a programming language for database development.We can write  functions and stored procedures.It is dynamic programming language for database.

3. Where we use SQL and PL/SQL?
Ans: We can use SQL and PL/SQL with any programming language for back-end process(database).It will all the high-level programming languages.

4. What is the concepts in SQL?
Ans: SQL mainly for 4 statements.
Select : Get the content from the database based on our requirement.
Insert : Insert the new values into database.
Update : Update the past data with the present  data in the database.
Delete : Remove or delete the unnecessary data from the database.
These statements are possible only with queries execute against the database. SQL is not case-sensitive.

5. Statement types in SQL?
Ans : There 5 types of statements in SQL.
1.Data Definition Language(DDL)
2. Data Manipulation Language(DML)
3. Data Control Language(DCL)
4. Transaction Control Language(TCL)
5. Dynamic Query Language(DQL)

Monday, 19 March 2012

Why Data Ware Housing


Data ware house - Data Base for Analysis and Reporting. 

Why we need Data ware Housing? 
Data ware house is a database for Analysis and Reporting not for transaction processing but we can include from other data sources. In organizations,to find the current status,forecast the values and add the forecast values to the database.Data ware house maintains the historical data of database(i.e.,Transaction data).

Data ware housing process
Data ware Housing is a process extracting data from Database(OLTP-online Transaction process) system and load the data into Dataware house(OLAP-Online Analytical processing).We can also add the forecast values to the database.

Saturday, 17 March 2012

Why Oracle?


Oracle-Huge database technology.

Why big organizations are use only Oracle as database?
Oracle database is a relational database management system which is a platform independent software can run and work in any environment and platform. It supports all the applications which may be developed in  any language software.
Why oracle takes a lead role in the software industry?
Oracle is used for almost all large application and one of the main applications in which oracle takes its major presence is banking sector. In fact ten of the world’s top 10 banks run Oracle applications this is because oracle offers a powerful combination of technology and comprehensive, pre-integrated business applications, including key functionality built specifically for banks.
Also with the features available in oracle with the earlier versions in market the oracle company keeps upgrading and releasing new products into market, new versions releases which serves better than the earlier versions and thus the performance is improved much in later versions and thereby retaining the market growth and thus proves greater satisfaction to the customers using this technology. Thus the advantage of a higher version is that one would have more features and better capabilities.
Thus oracle provides advantages and features that give security, protection, maintenance, reliability and performance on operation of data and with this in addition its main popularity and stability is because it keeps on adding new features which makes it user friendly for users and popularly used database among organizations.
Oracle technology not only for data storage also for data analysis i.e., Data ware housing for Healthcare, Education, Insurance, Enterprises etc. Oracle provides different technologies SQL Developer, OWB, ODI, OBIEE, Oracle Fusion Middle ware and BI Publisher etc.

Wednesday, 7 March 2012

Oracle Technology Inspiration

We Jyothi and Prasanna are working as software engineer, holds B-tech degree in ECE and IT respectively.We are very much interested in technical blogging. This blog mainly concentrates on oracle technologies. The posts will be on oracle concepts, interview question and answers, real time scenarios, solutions for queries, related jobs and url's for specific topics are provided.

         This blog will be very helpful for the candidates learning the technology and looking for the job and also for the oracle professionals to update their skills.




Candidate should learn the Concepts in Pl/Sql

Concepts in Pl/Sql:
  • Pl/Sql architecture, datatypes, variables and constants
  • Using built in functions, sql within pl/sql
  • Conditional and unconditional statements
  • Iterations in pl/sql
  • Composite datatypes
  • Cursors(Implicit and Explicit)
  • Records, pl/sql table types
  • Procedures
  • Functions
  • Packages
  • Exceptions
  • Triggers
Sql Interview Questions and answers

Candidate should learn the concepts in SQL

Concepts in SQL:

  • Basic terms and introduction in RDBMS technology
  • Sub language commands like DDL, DML, DRL, TCL, DCL
  • Built in functions
  • Grouping the result
  • Integrity constraints
  • Joins
  • Sub-queries
  • Database objects like Views, Sequences, Synonyms, Index, Clusters
  • Pseudo columns
  • partitions & parallel process
  • Locks