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 find [DbVisualizer](http://www.dbvis.com/) to be outstanding even when compared to many native tools.

![DbVisualizer Features](https://i.stack.imgur.com/nK5Be.png)