Linux Directory Structure (File System Structure) Explained with Examples by Ramesh Natarajan on September 8, 2010 Have you wondered why certain programs are located under /bin, or /sbin, or /usr/bin, or /usr/sbin? For example, less command is located under /usr/bin directory. Why not /bin, or /sbin, or /usr/sbin? What is the different between all these directories? In this article, let us review the Linux filesystem structures and understand the meaning of individual high-level directories. 1. / – Root Every single file and directory starts from the root directory.Only root user has write privilege under this directory.Please note that /root is root user’s home directory, which is not same as /. 2. Contains binary executables.Common linux commands you need to use in single-user modes are located under this directory.Commands used by all the users of the system are located here.For example: ps, ls, ping, grep, cp. 3. 4. 5. Contains device files.These include terminal devices, usb, or any device attached to the system.For example: /dev/tty1, /dev/usbmon0 6. 7. 8. 9.
SQL Interview Questions SQL Interview Questions(few questions are repeated with small differences in their answers) What Is SQL? SQL (pronounced as the letters S-Q-L or as sequel) is an abbreviation for Structured Query Language. SQL is a language designed specifically for communicating with databases. Which command displays the SQL command in the SQL buffer, and then executes it? What is the difference between Truncate & Drop? Answer Explain SQL Having? Answer Difference between SQL Having & Where? Answer Difference between SQL IN/SQL Exists? Answer Difference between SQL NOT IN/SQL NOT Exists? Answer Difference between SQL UNION/SQL UNION ALL? Answer Explain SQL TOP. Answer How to delete duplicate records in a table? Answer How to find duplicate records with the number they are duplicated? SELECT Id, count (*) as num_records from table group by id having count (*) > 1 What is a PRIMARY KEY? The PRIMARY KEY is the column(s) used to uniquely identify each row of a table. What is a FOREIGN KEY? What is a UNIQUE KEY? Answer Answer Answer
Forget WiFi, Its LiFi: Internet Through Lightbulbs Whether you’re using wireless internet in a coffee shop, stealing it from the guy next door, or competing for bandwidth at a conference, you’ve probably gotten frustrated at the slow speeds you face when more than one device is tapped into the network. As more and more people—and their many devices—access wireless internet, clogged airwaves are going to make it increasingly difficult to latch onto a reliable signal. But radio waves are just one part of the spectrum that can carry our data. What if we could use other waves to surf the internet? One German physicist, Harald Haas, has come up with a solution he calls “data through illumination”—taking the fiber out of fiber optics by sending data through an LED lightbulb that varies in intensity faster than the human eye can follow. It’s the same idea behind infrared remote controls, but far more powerful. Photo (cc) via otto-otto.com
Technote (FAQ) iis6 - How do you work out the IIS Virtual Path for an application osh and score and logic behind the processes How to Find Keywords For Effective SEO In other words, keywords are tools used to help you improve your search rankings. Their strategic use in Internet marketing is one of the most important search engine optimization (SEO) strategies. A highly visible and successful site depends on your understanding of keywords (choosing the right ones, where to find them, best ways to use them). Using the right keywords may list your page among the first 20 sites returned by search engines and the wrong keywords may bury your pages under hundreds of results returned before your site. How to choose the right keywords? Before you can choose the right keywords, you need to know how keywords are classified. Ø Brand Keywords – are those keywords contained in your business name, business description or specific category of business. Ø Generic Keywords – are keywords which are not directly associated with your company brand, but those which indirectly describe what you are offering or selling. Brainstorming: Broad keywords vs. Organic keywords
14 Good design tips in Datastage 1) When you need to run the same sequence of jobs again and again, better create a sequencer with all the jobs that you need to run. Running this sequencer will run all the jobs. You can provide the sequence as per your requirement. 2) If you are using a copy or a filter stage either immediately after or immediately before a transformer stage, you are reducing the efficiency by using more stages because a transformer does the job of both copy stage as well as a filter stage 3) Use Sort stages instead of Remove duplicate stages. Sort stage has got more grouping options and sort indicator options. 4) Turn off Runtime Column propagation wherever it’s not required. 5) Make use of Modify, Filter, and Aggregation, Col. 6)Avoid propagation of unnecessary metadata between the stages. 7)Add reject files wherever you need reprocessing of rejected records or you think considerable data loss may happen. 8)Make use of Order By clause when a DB stage is being used in join.
Business Intelligence (BusinessObjects) - Crystal Reports 2008 - Version and Download information for SPs and FPs Skip to end of metadataGo to start of metadata For a current AND temporary download of SP 5 please see the CR 2008 reference page ** Note; Service Pack 2, contains all earlier fixes up to and including FP1.5. To install SP 2, you must install SP 1 first. For more information see the blog Topic of the Week - Crystal Reports, Report Application Server, Business Objects Enterprise, post from 7/31/2009. # Note; Service Pack 3 contains all fixes up to and including Fix Pack 2.5. To find the Crystal Reports version, click Help > About Update Feb. 10, 2010; A request has been received to add links or information to this wiki regarding what is actually fixed in each FP. Update March 8, 2010; A wiki titled Resolved issues for Crystal Reports & InProc RAS SDK for VS .NET has been created. Update November 2, 2010; For fix pack and service information for CR 9.1 to 12 see the blog Crystal Reports 2008 (and 9.1, XI R1, XI R2) - Version and Download information for Service Packs & Fix Packs
PLSQL Oracle is a relational database technology developed by Oracle. PLSQL stands for "Procedural Language extensions to SQL", and is an extension of SQL that is used in Oracle. PLSQL is closely integrated into the SQL language, yet it adds programming constructs that are not native to SQL. Our tutorial will start with the basics of Oracle such as how to retrieve and manipulate data. With this tutorial, you should be on your way to becoming proficient in Oracle and PLSQL. There are no prequisities for this Oracle tutorial. Now, let's get started! Start Tutorial Black Viper’s Windows 7 Service Pack 1 Service Configurations Introduction To continue my fine tradition of optimizing MS’s latest OS, I have here my findings to date. If you are looking for Windows 7 Retail information, you are almost in the right spot. Before adjusting your service settings, ensure that your system has already installed all updates by “checking now” for any available updates via Windows Update. Breakdown of all changes to date: Windows 7 Information Changelog. I cannot possibly test all configurations extensively (meaning, each persons specific computer needs), but what I can offer is what “works for me” and the obstacles I have came across so you do not have to discover them on your own. An * (asterisk) indicates changes from the default Two ** (asterisks) indicates you can add or remove this service by: Head to StartSelect Control PanelSelect ProgramsSelect Programs and FeaturesSelect Turn Windows Features on or off Three *** (asterisks) indicates optional services installed with Windows Live Essentials. Table Header Information
1NF, 2NF, 3NF and BCNF in Database Normalization Normalization of Database Normalization is a systematic approach of decomposing tables to eliminate data redundancy and undesirable characteristics like Insertion, Update and Deletion Anamolies. It is a two step process that puts data into tabular form by removing duplicated data from the relation tables. Normalization is used for mainly two purpose, Eliminating reduntant(useless) data.Ensuring data dependencies make sense i.e data is logically stored. Problem Without Normalization Without Normalization, it becomes difficult to handle and update the database, without facing data loss. Normalization Rule Normalization rule are divided into following normal form. First Normal FormSecond Normal FormThird Normal FormBCNF First Normal Form (1NF) A row of data cannot contain repeating group of data i.e each column must have a unique value. Student Table : You can clearly see here that student name Adam is used twice in the table and subject math is also repeated. New Student Table : Subject Table :