May 31, 2014

Getting started with MongoDB

MongoDB is currently the most popular NoSQL database out there to store "Big Data". The name "Mongo" come from humongous (means huge). MongoDB stores data as JSON documents as opposed to records in a relational table. A collection of documents in MongoDB is similar to a table in traditional databases. Some useful features MongoDB provides includes ad hoc document based queries, indexing, load balancing, replication across LANs and WANs, mapreduce algorithms for data processing and aggregation and auto-sharding (scales horizontally by adding extra machines).

Many companies (MetLife, eBay, LinkedIn, The New York Times to name a few) have already adopted MongoDB for their data management needs. The insurance company MetLife created a facebook like interface called The Wall which provides "360-degree, consolidated view of MetLife customers, including policy details and transactions across lines of business".

To get started with MongoDB, try the online MondoDB shell at It has a very short tutorial on how to perform basic database operations like, insert, update and retrieve records.

To create a document in the users collection, enter:
db.users.insert({name:'John', age:30, email:''});

Now to select all users you would write:

Once you are done with the tutorial, you might want to install MongoDB on your machine. Actually, you can run it without installing. Just download the appropriate zip file for your OS. Unzip the folder on your machine and run the mongod.exe from command prompt. It would start the database server. From another command window, start mongo.exe and you would have the MongoDB shell ready to execute database commands. You can find the detailed installation guide here.

January 26, 2014

Funny Google search results

Google really has some sense of humor. Here are some of the funniest search results you would find on Google. Try them yourself if you don't believe.

Search for: "binary"

Google Search - binary

Also try with "octal" and "hexadecimal"

August 5, 2012

Curiosity to land on Mars on August 6

The Mars Science Laboratory (MSL), also known as the Curiosity rover will finally land on Mars on August 6. It was launched 8 months ago on November 26. I had even blogged about it then! The landing sequence is very interesting and complex. It takes only about 7 minutes from touching the Mars atmosphere and landing on the ground.

June 2, 2012

Start Countdown: We Collide Head-on with Andromeda in Just 4 Billion Years

New results from NASA scientists working with Hubble’s data, suggests with more certainty that our Milky Way galaxy will collide with the Andromeda galaxy in another 4 billion years.

We have long known that our neighbor Andromeda galaxy is hurtling towards us, and will probably collide us in the future. But we were not sure, if the collision will be head-on or it will miss us. Also we were not sure about the timing and impacts of this event. With more data from Hubble, we are now able to predict the collision with more certainty.

April 8, 2012

Amazon Kindle 4

I bought a Kindle 4 recently. It is a beautiful e-book reader - cheap, lightweight, slim, easy to hold in one hand. The E-Ink technology it uses, is really amazing. The screen seems almost like paper, without any glare, readable in direct sunlight. And the letters on it are solid, you don't see individual pixels. The first time I opened the device, I mistook the screen for a paper cover on it! The device came with a USB data cable which can be used to transfer books and documents. It is also charged via the USB cable. It has super long battery life. One full charge is supposed to last for a month, if you read half an hour daily. I also like the inbuilt Oxford dictionary. You can instantly look-up any word in the dictionary, without leaving the current page. It has page turning buttons on both left and right side, which are very useful for shifting the device from one hand to the other.

February 26, 2012

Into the World of Computer Gaming

I had a Desktop PC with Gigabyte G31M-S2L motherboard, Intel Core 2 Duo processor and 2GB RAM for a long time. But, it didn't have any dedicated graphics card. Most computer games wouldn't work on my PC. Recently, I bought a descent mid-range graphics card (AMD Raedon 6670 1 GB DDR5) for Rs. 5400. Now, I can play almost all the latest games in High Resolution.

January 14, 2012

Be a Schemer!

Google had launched Schemer a few months back. I recently got an invitation and signed up. It is a good concept. It is basically a service to keep track of the things you want to do in life. But it is more than just a notebook. You can find recommendations from friends, experts and celebrities about the things that are worth doing. It may be exploring a new city, watching a movie your friend recommends, or finding new activities for your weekends. You can also create your own schemes and share it with the world, or keep it private if you like.

Overall, I like the concept. Often, we think of something awesome to do (in future). But usually, after a few hours or days we forget all about it among other day-to-day matters. This is where Schemer can help. It can remind you of all the things you want to do in life. Of course, you have to remember to check Schemer, once in a while!

I have got some invitations. If you are waiting for one, try the below link. Though the service is available worldwide, location based recommendations may not work well outside US.