Question: What are the query browsers for DB2 e.g Database Administrator(Data Studio), Toad for DB2 etc? I worked with them but are there more ?

Answer: 
You can find a list of browsers in Wikipedia: 

<http://en.wikipedia.org/wiki/Comparison_of_database_tools#General> 

and look at "Other" column. You will see which tools work with DB2.

The popular ones are:

* Toad for DB2 <http://www.toadworld.com/products#ibm-db2>
* SQuirreL <http://www.squirrelsql.org>
* SQL Maestro <http://www.sqlmaestro.com/products/db2/maestro/>
* Altova DatabaseSpy <http://www.altova.com/databasespy.html>
* Embarcardero PowerStudio for DB2 <http://www.embarcadero.com/products/db-powerstudio-for-db2>

Or

* IBM Data Studio (Free) <http://www-01.ibm.com/software/data/optim/data-studio/>
* Technology Explorer (from IBM, on PHP) <http://sourceforge.net/projects/db2mc/>
* Control Center (Deprecated, included in IBM Data server client)
I recommend the IBM data studio among the free tools. It lets you

* Manipulate(Create , modify, execute) stored procedures
* See explain plans - run performance analysis
* Let you open unlimited connections which some of the free tools doesn't let you.

Also, it's based on eclipse framework, so if you are already using eclipse its almost a breeze to learn. Toad freeware is also cool, however the freeware has a licensing limitation of max 5 per enterprise.

Also, check the [latest IBM data studio download](http://www.ibm.com/developerworks/downloads/im/data/)