Posts

Group by Date when Stored in Mysql DataBase as Date Time

I have a table called date_count with 2 columns one is a value and another is a date time, say called date_time in mysql. Date Time in mysql is stored as dd-mm-yy hh:mm:ss. The issue comes when I need to get the number of rows per day. As its stored as dat …

Important MySQL DBA Interview Questions

Here are a few sets of interview questions expected for MySQL DBA position.These are compilation of the usual questions from various DBA texts: What is Log Switch? – The point at which ORACLE ends writing to one online redo log file and begins writing to …

Generate Date from a range in Mysql and pad the results where no date is present

If you want to generate dates, MYSQL doesn’t have a range function, so I wrote a work around for the same. So how  it works is I have reused a code to generate numbers from my previous post. So I added date function to that query and reduce the generated  …

Find Invisible Users In Gmail

Finding who is invisible is something that I always wanted to do.It’s always fun to ping a person who feels none can see him/her online. While studying XMPP protocol I found out that even when the person is offline the chat client knows that person is onli …

Birthday Reminder For Gnome Panel

This program checks the file /home/rsrijith/shell/birthday_reminder.txt to find the upcoming birthdays in 20 days and writes into the file /home/rsrijith/shell/birthdays. There is a file called /home/rsrijith/shell/birthdays1, the difference between it and …

BSNL Dataone Auto Downloader

Bsnl(India) provides an account that has 2am to 8am unlimited download. It was not easy to wake up at 2am and switch on the computer and sleep again. So I tried to find a method to switch on the computer automatically at 2am and download and shutdown at 8a …

Automatic Command Archive

The default command storing size of ubuntu is 500 commands. It stores the commands in home folder in the file “.bash_history” . The problem is 500 commands is too short of a size. One method is to increase the command size to a large value by changing the  …

Service Engineer/System Administrator Interview Questions

This is not my code alone.  It was the group effort of Vivek Ram, Cijo George, Sandeep Unni and mine during our epic preparation for Yahoo!. I am just putting it open for others who would be looking for this information. Convert all lower case to upper  …

Sort according to the nth Column in Shell Script

You have a file that has multiple columns separated by a specific delimiter and you need to sort it according to a specific column which need not be the 1st column. If its not the 1st column then ordinary sort wont work. So we need to use the parameters of …

Reminder for Gnome Panel

This is the program that lets us to enter the text and time at which it should be reminded me. The command has the following options -d: date eg:  17/3/2009 -t : time [ It’s should be entered as 24hr clock] eg:   20:00:00 -r : reminder text [ It sho …